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#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <math.h>
#include <stdio.h>
#include <deque>
#include <unordered_map>
#include <cassert>
#include <numeric>
#include <queue>
#include <list>
#include <bitset>

using namespace std;
#define ULL unsigned long long

static int ROWS, COLS;

struct Fraction {
    int top,bottom;
    Fraction(int a,int b) : top(a), bottom(b) {};

    double val() {
        return (double)top / (double)bottom;
    }
};

struct Plansza {
    bitset<64> cell;
    Plansza() {}

    void set_row(int r, string s) {
        for (int i=0; i < s.size(); i++)
        {
            cell[r*8 + i] = s[i] == 'O' ? 1 : 0;
        }
    }

    ULL id() {
        return cell.to_ullong();
    }

    bool operator==(const Plansza &other)
    {
        return this->cell == other.cell;
    }

    bool within_bounds(int r, int c) 
    {
        if (r < 0 || r >= ROWS) return false;
        if (c < 0 || c >= COLS) return false;

        return true;
    }

    int idFrom(int r, int c) {
        return r * 8 + c;
    }

    vector<Plansza> getAdj() {
        vector<Plansza> res;
        const vector<pair<int, int> > DIR = {{1,0}, {-1, 0}, {0, 1}, {0,-1}};
        for (int r=0; r < ROWS; r++)
        {
            for (int c=0; c < COLS; c++)
            {
                if (!cell[idFrom(r,c)]) continue;
                for (int dir=0; dir < 4; dir++)
                {
                    int nr = r + DIR[dir].first;
                    int nc = c + DIR[dir].second;
                    if (!within_bounds(nr, nc)) continue;
                    if (cell[idFrom(nr, nc)]) continue;
                    Plansza next = *this;
                    next.cell[idFrom(r,c)] = 0;
                    next.cell[idFrom(nr, nc)] = 1;
                    res.push_back(next);
                }
            }
        }
        return res;
    }
    void print() {
        for (int r=0; r < ROWS; r++) {
            for (int c=0; c < COLS; c++) {
                printf("%c", cell[r*8+c] ? 'O' : '.');
            }
            printf("\n");
        }
    }
};



unordered_map<ULL, vector<Plansza> > bfs(Plansza p, Plansza dest) {

    queue<Plansza> Q;
    Q.push(p);
    unordered_map<ULL, bool> seen;
    unordered_map<ULL, vector<Plansza> > transtions;

    while (!Q.empty()) {
        Plansza current = Q.front(); Q.pop();
        if (seen[current.id()]) continue;
        seen[current.id()] = true;
        //printf("current: %llu\n", current.id()); current.print();
    
        vector<Plansza> adj = current.getAdj();
        //printf("next: ");
        for (auto &next : adj) {
            //printf("%llu[%d/%d],", next.first.id());
            Q.push(next);
        }
        transtions[current.id()] = adj;

        //printf("\n");
    }
    //printf("All states: %d\n", transtions.size());
    //printf("END\n");
    return transtions;
}

double random_walk(Plansza start, unordered_map<ULL, vector<Plansza> > transitions, Plansza dest) {
    unordered_map<ULL, double> dpCurrent, dpNext;
    
    for (auto &it : transitions) {
        dpCurrent[it.first] = 0.0;
    }
    dpCurrent[start.id()] = 1.0;
    
    for (int step=1; step <= 1000; step++)
    {
        //printf("Step %d\n", step);
        for (auto &it : transitions) {
            ULL v = it.first;
            double dpNextV = 0.0;
            auto adj = it.second;
            //printf("%d adj size for v=%llu\n", adj.size(), v);
            for (Plansza &next : adj) {
                ULL u = next.id();
                
                double dpU = dpCurrent[u];
                int degU = transitions[u].size();
                assert (degU > 0);
                //printf("dpNextV: u=%ld, dpU=%lf, degU=%lf,", u, dpU, degU);
                dpNextV += dpCurrent[u] / degU;
            }
            //printf("\n");
            dpNext[v] = dpNextV;
        }
        dpCurrent = dpNext;
        //printf("Step: %d:", step); for (auto &it : dpCurrent) { printf("%lld->%.3lf: ", it.first, it.second); } printf("\n");
        //printf("Step: %d Dest probability: %lf\n", step, dpCurrent[dest.id()]);
    }
    return dpCurrent[dest.id()];  
}

int main() {

    scanf("%d%d", &ROWS, &COLS);
    char buf[20];
    Plansza p;
    for (int i=0; i < ROWS; i++)
    {
        scanf("%s", &buf);
        p.set_row(i, string(buf));
    }

    Plansza dest;
    for (int i=0; i < ROWS; i++) {
        scanf("%s", &buf);
        dest.set_row(i, string(buf));
    }
    auto transitions = bfs(p, dest);
    double res = random_walk(p, transitions, dest);
    //dest.print();
    printf("%.13lf\n", res);
    return 0;
}