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#include <iostream>

double Newton(unsigned int n, unsigned int k)
{
    double result = 1;
    for (unsigned int i = 1; i <= k; i++)
        result = result * (n - i + 1) / i;

    return (double) result;
}

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    int n, m; std::cin >> n >> m;

    int wh_total = 0, bl_total = 0;

    int wh1 = 0, bl1 = 0;

    for (int i = 0; i < n; i++)
    {
        bool is_wh = (i % 2) == 1;
        for (int j = 0; j < m; j++)
        {
            is_wh = !is_wh;
            if (is_wh) wh_total++;
            else bl_total++;
            char c; std::cin >> c;
            if (c != 'O') continue;
            if (is_wh) wh1++;
            else bl1++;
        }
    }
    
    int wh2 = 0, bl2 = 0;

    for (int i = 0; i < n; i++)
    {
        bool is_wh = (i % 2) == 1;
        for (int j = 0; j < m; j++)
        {
            is_wh = !is_wh;
            char c; std::cin >> c;
            if (c != 'O') continue;
            if (is_wh) wh2++;
            else bl2++;
        }
    }

    if (wh1 != wh2) { std::cout << 0; return 0; }
    
    std::cout << (1 / (Newton(wh_total, wh1) * Newton(bl_total, bl1)));
    
    return 0;
}