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#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <string>

using namespace std;

#define MAX 1000000
#define DB if(0)
#define PR if(0)
#define RND if (0)

string in[8], out[8];
double markov[8][8], old[8][8], errComp[8][8];
int counts[8][8];
double maxErr = 1e-17;
int n, m;

void copy() {
    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            old[i][j] = markov[i][j];
        }
    }
}

void copyErr() {
    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            errComp[i][j] = markov[i][j];
        }
    }
}

void print() {
    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            printf("%.2f ", markov[i][j]);
        }
        printf("\n");
    }
}

void setCounts() {
    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            for (int k=-1; k<=1; k++) {
                for (int l=-1; l<=1; l++) {
                    if (k + l != 0 && k * l == 0 && i + k >= 0 && j + l >= 0 && i + k < n && j + l < m) {
                        counts[i][j]++;
                    }
                }
            }
        }
    }

    PR for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            printf("%d ", counts[i][j]);
        }
        printf("\n");
    }
}

bool checkErr() {
    double error = 0;
    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            PR printf("err: %.2f, max: %.2f\n", markov[i][j] - errComp[i][j], error);
            error = max(error, abs(markov[i][j] - errComp[i][j]));
        }
    }

    PR printf("err: %.9f vs %.9f\n", error, maxErr);

    return error < maxErr;
}

void update() {
    PR printf("\n----------\n");
    PR print();
    copy();

    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            markov[i][j] = 0;
            for (int k=-1; k<=1; k++) {
                for (int l=-1; l<=1; l++) {
                    if (k + l != 0 && k * l == 0 && i + k >= 0 && j + l >= 0 && i + k < n && j + l < m) {
//                        printf("markov[%d][%d] += [%d][%d] (%.2f / %d = %.2f)\n", i, j, i+k, j+l, old[i+k][j+l], counts[i+k][j+l], old[i+k][j+l] / counts[i+k][j+l]);
                        markov[i][j] += old[i+k][j+l] / counts[i+k][j+l];
                    }
                }
            }
//            markov[i][j] *= (1 - old[i][j]); // Case when pawn was on the position
        }
    }
}

int main() {
    cin >> n >> m;

    for (int i=0; i<n; i++) cin >> in[i];
    for (int i=0; i<n; i++) cin >> out[i];

    setCounts();

    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            markov[i][j] = in[i][j] == 'O';
        }
    }

    int round = 0;
    while (true) {
        copyErr();
        update();

        update();
        if (checkErr()) {
            PR printf("DONE");
            break;
        }
        round++;
        if (round > MAX) break;
    }

//    print();
    double result = 1;


    for (int i=0; i<n; i++) {
        for (int j=0; j<m; j++) {
            if (out[i][j] == 'O') result *= markov[i][j];
        }
    }

    printf("%.17f", result);
}