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#include <bits/stdc++.h>
 
using namespace std;
 
#define endl '\n'
#define L long long
#define MP make_pair
#define REP(i, n) for(int i = 0; i < n; ++i)
#define REPR(i, n) for(int i = n - 1; i >= 0; --i)
#define FOR(i, a, b) for(int i = a; i < b; ++i)
#define FORR(i, a, b) for(int i = b - 1; i >= a; --i)
#define EB emplace_back
#define ST first
#define ND second
#define S size
#define RS resize
 
template<class T> using P = pair<T, T>;
template<class T> using V = vector<T>;

int n, m, k = 0;

L count_neigh(V<string>& p) {
    L res = 0;
    REP(i, n) {
        REP(j, m) {
            if (i < n - 1 && p[i][j] + p[i + 1][j] == 'O' + '.') {
                res++;
            }
            if (j < m - 1 && p[i][j] + p[i][j + 1] == 'O' + '.') {
                res++;
            }
        }
    }
    return res;
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> m;
    V<string> p1(n), p2(n);
    REP(i, n) {
        cin >> p1[i];
    }
    REP(i, n) {
        cin >> p2[i];
    }

    int m1 = 0, m2 = 0;
    REP(i, n) {
        REP(j, m) {
            if (p1[i][j] == 'O') {
                m1 += i + j;
                k++;
            }
            if (p2[i][j] == 'O') {
                m2 += i + j;
            }
        }
    }

    if (m1 % 2 != m2 % 2) {
        cout << 0;
        return 0;
    }
    
    L res[9][9][9];
    L neigh = count_neigh(p2);
    res[1][2][1] = 1;
    res[1][3][1] = 2;
    res[1][3][2] = 2;
    res[1][4][1] = 3;
    res[1][4][2] = 6;
    res[1][4][3] = 3;
    res[1][5][1] = 4;
    res[1][5][2] = 12;
    res[1][5][3] = 12;
    res[1][5][4] = 4;
    res[1][6][1] = 5;
    res[1][6][2] = 20;
    res[1][6][3] = 30;
    res[1][6][4] = 20;
    res[1][6][5] = 5;
    res[1][7][1] = 6;
    res[1][7][2] = 30;
    res[1][7][3] = 60;
    res[1][7][4] = 60;
    res[1][7][5] = 30;
    res[1][7][6] = 6;
    res[1][8][1] = 7;
    res[1][8][2] = 42;
    res[1][8][3] = 105;
    res[1][8][4] = 140;
    res[1][8][5] = 105;
    res[1][8][6] = 42;
    res[1][8][7] = 7;
    res[2][1][1] = 1;
    res[2][2][1] = 4;
    res[2][2][2] = 8;
    res[2][2][3] = 4;
    res[2][3][1] = 7;
    res[2][3][2] = 28;
    res[2][3][3] = 42;
    res[2][3][4] = 28;
    res[2][3][5] = 7;
    res[2][4][1] = 10;
    res[2][4][2] = 60;
    res[2][4][3] = 150;
    res[2][4][4] = 200;
    res[2][4][5] = 150;
    res[2][4][6] = 60;
    res[2][4][7] = 10;
    res[2][5][1] = 13;
    res[2][5][2] = 104;
    res[2][5][3] = 364;
    res[2][5][4] = 728;
    res[2][5][5] = 910;
    res[2][5][6] = 728;
    res[2][5][7] = 364;
    res[2][5][8] = 104;
    res[2][6][1] = 16;
    res[2][6][2] = 160;
    res[2][6][3] = 720;
    res[2][6][4] = 1920;
    res[2][6][5] = 3360;
    res[2][6][6] = 4032;
    res[2][6][7] = 3360;
    res[2][6][8] = 1920;
    res[2][7][1] = 19;
    res[2][7][2] = 228;
    res[2][7][3] = 1254;
    res[2][7][4] = 4180;
    res[2][7][5] = 9405;
    res[2][7][6] = 15048;
    res[2][7][7] = 17556;
    res[2][7][8] = 15048;
    res[2][8][1] = 22;
    res[2][8][2] = 308;
    res[2][8][3] = 2002;
    res[2][8][4] = 8008;
    res[2][8][5] = 22022;
    res[2][8][6] = 44044;
    res[2][8][7] = 66066;
    res[2][8][8] = 75504;
    res[3][1][1] = 2;
    res[3][1][2] = 2;
    res[3][2][1] = 7;
    res[3][2][2] = 28;
    res[3][2][3] = 42;
    res[3][2][4] = 28;
    res[3][2][5] = 7;
    res[3][3][1] = 12;
    res[3][3][2] = 84;
    res[3][3][3] = 252;
    res[3][3][4] = 420;
    res[3][3][5] = 420;
    res[3][3][6] = 252;
    res[3][3][7] = 84;
    res[3][3][8] = 12;
    res[3][4][1] = 17;
    res[3][4][2] = 170;
    res[3][4][3] = 765;
    res[3][4][4] = 2040;
    res[3][4][5] = 3570;
    res[3][4][6] = 4284;
    res[3][4][7] = 3570;
    res[3][4][8] = 2040;
    res[3][5][1] = 22;
    res[3][5][2] = 286;
    res[3][5][3] = 1716;
    res[3][5][4] = 6292;
    res[3][5][5] = 15730;
    res[3][5][6] = 28314;
    res[3][5][7] = 37752;
    res[3][5][8] = 37752;
    res[3][6][1] = 27;
    res[3][6][2] = 432;
    res[3][6][3] = 3240;
    res[3][6][4] = 15120;
    res[3][6][5] = 49140;
    res[3][6][6] = 117936;
    res[3][6][7] = 216216;
    res[3][6][8] = 308880;
    res[3][7][1] = 32;
    res[3][7][2] = 608;
    res[3][7][3] = 5472;
    res[3][7][4] = 31008;
    res[3][7][5] = 124032;
    res[3][7][6] = 372096;
    res[3][7][7] = 868224;
    res[3][7][8] = 1612416;
    res[3][8][1] = 37;
    res[3][8][2] = 814;
    res[3][8][3] = 8547;
    res[3][8][4] = 56980;
    res[3][8][5] = 270655;
    res[3][8][6] = 974358;
    res[3][8][7] = 2760681;
    res[3][8][8] = 6310128;
    res[4][1][1] = 3;
    res[4][1][2] = 6;
    res[4][1][3] = 3;
    res[4][2][1] = 10;
    res[4][2][2] = 60;
    res[4][2][3] = 150;
    res[4][2][4] = 200;
    res[4][2][5] = 150;
    res[4][2][6] = 60;
    res[4][2][7] = 10;
    res[4][3][1] = 17;
    res[4][3][2] = 170;
    res[4][3][3] = 765;
    res[4][3][4] = 2040;
    res[4][3][5] = 3570;
    res[4][3][6] = 4284;
    res[4][3][7] = 3570;
    res[4][3][8] = 2040;
    res[4][4][1] = 24;
    res[4][4][2] = 336;
    res[4][4][3] = 2184;
    res[4][4][4] = 8736;
    res[4][4][5] = 24024;
    res[4][4][6] = 48048;
    res[4][4][7] = 72072;
    res[4][4][8] = 82368;
    res[4][5][1] = 31;
    res[4][5][2] = 558;
    res[4][5][3] = 4743;
    res[4][5][4] = 25296;
    res[4][5][5] = 94860;
    res[4][5][6] = 265608;
    res[4][5][7] = 575484;
    res[4][5][8] = 986544;
    res[4][6][1] = 38;
    res[4][6][2] = 836;
    res[4][6][3] = 8778;
    res[4][6][4] = 58520;
    res[4][6][5] = 277970;
    res[4][6][6] = 1000692;
    res[4][6][7] = 2835294;
    res[4][6][8] = 6480672;
    res[4][7][1] = 45;
    res[4][7][2] = 1170;
    res[4][7][3] = 14625;
    res[4][7][4] = 117000;
    res[4][7][5] = 672750;
    res[4][7][6] = 2960100;
    res[4][7][7] = 10360350;
    res[4][7][8] = 29601000;
    res[4][8][1] = 52;
    res[4][8][2] = 1560;
    res[4][8][3] = 22620;
    res[4][8][4] = 211120;
    res[4][8][5] = 1425060;
    res[4][8][6] = 7410312;
    res[4][8][7] = 30876300;
    res[4][8][8] = 105861600;
    res[5][1][1] = 4;
    res[5][1][2] = 12;
    res[5][1][3] = 12;
    res[5][1][4] = 4;
    res[5][2][1] = 13;
    res[5][2][2] = 104;
    res[5][2][3] = 364;
    res[5][2][4] = 728;
    res[5][2][5] = 910;
    res[5][2][6] = 728;
    res[5][2][7] = 364;
    res[5][2][8] = 104;
    res[5][3][1] = 22;
    res[5][3][2] = 286;
    res[5][3][3] = 1716;
    res[5][3][4] = 6292;
    res[5][3][5] = 15730;
    res[5][3][6] = 28314;
    res[5][3][7] = 37752;
    res[5][3][8] = 37752;
    res[5][4][1] = 31;
    res[5][4][2] = 558;
    res[5][4][3] = 4743;
    res[5][4][4] = 25296;
    res[5][4][5] = 94860;
    res[5][4][6] = 265608;
    res[5][4][7] = 575484;
    res[5][4][8] = 986544;
    res[5][5][1] = 40;
    res[5][5][2] = 920;
    res[5][5][3] = 10120;
    res[5][5][4] = 70840;
    res[5][5][5] = 354200;
    res[5][5][6] = 1345960;
    res[5][5][7] = 4037880;
    res[5][5][8] = 9806280;
    res[5][6][1] = 49;
    res[5][6][2] = 1372;
    res[5][6][3] = 18522;
    res[5][6][4] = 160524;
    res[5][6][5] = 1003275;
    res[5][6][6] = 4815720;
    res[5][6][7] = 18460260;
    res[5][6][8] = 58017960;
    res[5][7][1] = 58;
    res[5][7][2] = 1914;
    res[5][7][3] = 30624;
    res[5][7][4] = 316448;
    res[5][7][5] = 2373360;
    res[5][7][6] = 13765488;
    res[5][7][7] = 64238944;
    res[5][7][8] = 247778784;
    res[5][8][1] = 67;
    res[5][8][2] = 2546;
    res[5][8][3] = 47101;
    res[5][8][4] = 565212;
    res[5][8][5] = 4945605;
    res[5][8][6] = 33630114;
    res[5][8][7] = 184965627;
    res[5][8][8] = 845557152;
    res[6][1][1] = 5;
    res[6][1][2] = 20;
    res[6][1][3] = 30;
    res[6][1][4] = 20;
    res[6][1][5] = 5;
    res[6][2][1] = 16;
    res[6][2][2] = 160;
    res[6][2][3] = 720;
    res[6][2][4] = 1920;
    res[6][2][5] = 3360;
    res[6][2][6] = 4032;
    res[6][2][7] = 3360;
    res[6][2][8] = 1920;
    res[6][3][1] = 27;
    res[6][3][2] = 432;
    res[6][3][3] = 3240;
    res[6][3][4] = 15120;
    res[6][3][5] = 49140;
    res[6][3][6] = 117936;
    res[6][3][7] = 216216;
    res[6][3][8] = 308880;
    res[6][4][1] = 38;
    res[6][4][2] = 836;
    res[6][4][3] = 8778;
    res[6][4][4] = 58520;
    res[6][4][5] = 277970;
    res[6][4][6] = 1000692;
    res[6][4][7] = 2835294;
    res[6][4][8] = 6480672;
    res[6][5][1] = 49;
    res[6][5][2] = 1372;
    res[6][5][3] = 18522;
    res[6][5][4] = 160524;
    res[6][5][5] = 1003275;
    res[6][5][6] = 4815720;
    res[6][5][7] = 18460260;
    res[6][5][8] = 58017960;
    res[6][6][1] = 60;
    res[6][6][2] = 2040;
    res[6][6][3] = 33660;
    res[6][6][4] = 359040;
    res[6][6][5] = 2782560;
    res[6][6][6] = 16695360;
    res[6][6][7] = 80694240;
    res[6][6][8] = 322776960;
    res[6][7][1] = 71;
    res[6][7][2] = 2840;
    res[6][7][3] = 55380;
    res[6][7][4] = 701480;
    res[6][7][5] = 6488690;
    res[6][7][6] = 46718568;
    res[6][7][7] = 272524980;
    res[6][7][8] = 1323692760;
    res[6][8][1] = 82;
    res[6][8][2] = 3772;
    res[6][8][3] = 84870;
    res[6][8][4] = 1244760;
    res[6][8][5] = 13381170;
    res[6][8][6] = 112401828;
    res[6][8][7] = 768079158;
    res[6][8][8] = 4389023760;
    res[7][1][1] = 6;
    res[7][1][2] = 30;
    res[7][1][3] = 60;
    res[7][1][4] = 60;
    res[7][1][5] = 30;
    res[7][1][6] = 6;
    res[7][2][1] = 19;
    res[7][2][2] = 228;
    res[7][2][3] = 1254;
    res[7][2][4] = 4180;
    res[7][2][5] = 9405;
    res[7][2][6] = 15048;
    res[7][2][7] = 17556;
    res[7][2][8] = 15048;
    res[7][3][1] = 32;
    res[7][3][2] = 608;
    res[7][3][3] = 5472;
    res[7][3][4] = 31008;
    res[7][3][5] = 124032;
    res[7][3][6] = 372096;
    res[7][3][7] = 868224;
    res[7][3][8] = 1612416;
    res[7][4][1] = 45;
    res[7][4][2] = 1170;
    res[7][4][3] = 14625;
    res[7][4][4] = 117000;
    res[7][4][5] = 672750;
    res[7][4][6] = 2960100;
    res[7][4][7] = 10360350;
    res[7][4][8] = 29601000;
    res[7][5][1] = 58;
    res[7][5][2] = 1914;
    res[7][5][3] = 30624;
    res[7][5][4] = 316448;
    res[7][5][5] = 2373360;
    res[7][5][6] = 13765488;
    res[7][5][7] = 64238944;
    res[7][5][8] = 247778784;
    res[7][6][1] = 71;
    res[7][6][2] = 2840;
    res[7][6][3] = 55380;
    res[7][6][4] = 701480;
    res[7][6][5] = 6488690;
    res[7][6][6] = 46718568;
    res[7][6][7] = 272524980;
    res[7][6][8] = 1323692760;
    res[7][7][1] = 84;
    res[7][7][2] = 3948;
    res[7][7][3] = 90804;
    res[7][7][4] = 1362060;
    res[7][7][5] = 14982660;
    res[7][7][6] = 128850876;
    res[7][7][7] = 901956132;
    res[7][7][8] = 5282885916;
    res[7][8][1] = 97;
    res[7][8][2] = 5238;
    res[7][8][3] = 138807;
    res[7][8][4] = 2405988;
    res[7][8][5] = 30676347;
    res[7][8][6] = 306763470;
    res[7][8][7] = 2505235005;
    res[7][8][8] = 17178754320;
    res[8][1][1] = 7;
    res[8][1][2] = 42;
    res[8][1][3] = 105;
    res[8][1][4] = 140;
    res[8][1][5] = 105;
    res[8][1][6] = 42;
    res[8][1][7] = 7;
    res[8][2][1] = 22;
    res[8][2][2] = 308;
    res[8][2][3] = 2002;
    res[8][2][4] = 8008;
    res[8][2][5] = 22022;
    res[8][2][6] = 44044;
    res[8][2][7] = 66066;
    res[8][2][8] = 75504;
    res[8][3][1] = 37;
    res[8][3][2] = 814;
    res[8][3][3] = 8547;
    res[8][3][4] = 56980;
    res[8][3][5] = 270655;
    res[8][3][6] = 974358;
    res[8][3][7] = 2760681;
    res[8][3][8] = 6310128;
    res[8][4][1] = 52;
    res[8][4][2] = 1560;
    res[8][4][3] = 22620;
    res[8][4][4] = 211120;
    res[8][4][5] = 1425060;
    res[8][4][6] = 7410312;
    res[8][4][7] = 30876300;
    res[8][4][8] = 105861600;
    res[8][5][1] = 67;
    res[8][5][2] = 2546;
    res[8][5][3] = 47101;
    res[8][5][4] = 565212;
    res[8][5][5] = 4945605;
    res[8][5][6] = 33630114;
    res[8][5][7] = 184965627;
    res[8][5][8] = 845557152;
    res[8][6][1] = 82;
    res[8][6][2] = 3772;
    res[8][6][3] = 84870;
    res[8][6][4] = 1244760;
    res[8][6][5] = 13381170;
    res[8][6][6] = 112401828;
    res[8][6][7] = 768079158;
    res[8][6][8] = 4389023760;
    res[8][7][1] = 97;
    res[8][7][2] = 5238;
    res[8][7][3] = 138807;
    res[8][7][4] = 2405988;
    res[8][7][5] = 30676347;
    res[8][7][6] = 306763470;
    res[8][7][7] = 2505235005;
    res[8][7][8] = 17178754320;
    res[8][8][1] = 112;
    res[8][8][2] = 6944;
    res[8][8][3] = 211792;
    res[8][8][4] = 4235840;
    res[8][8][5] = 62478640;
    res[8][8][6] = 724752224;
    res[8][8][7] = 6885146128;
    res[8][8][8] = 55081169024;

    cout << fixed << setprecision(17);
    cout << (double)neigh / (double)res[n][m][k];
}

// g++ -std=c++20 -Wall -Wextra -Wshadow -Wconversion -D_GLIBCXX_DEBUG wie2.cpp -o wie2