#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cmath>

using namespace std;
typedef long double ld;
const int MaxN = 30;
const ld eps = 1e-8;
struct Point {
        int x, y;
        Point() {
                x = 0, y = 0;
        }
        Point(int X, int Y) {
                x = X, y = Y;
        }
};
const Point d[8] = {Point(0, 1), Point(0, -1), Point(1, 0),
        Point(1, 1), Point(1, -1), Point(-1, 0), Point(-1, 1), Point(-1, -1)};

Point start;
bool vis[MaxN][MaxN];
int ma[MaxN][MaxN];
ld g[MaxN * MaxN][MaxN * MaxN];
int num[MaxN][MaxN];
int i, j, k, l, n, m, r;
char ch;
ld ans[MaxN * MaxN], dans, mx;
int ind[MaxN * MaxN];

void dfs(Point v) {
        if (vis[v.x][v.y] || (v.x >= n || v.y >= m))
                return;
        vis[v.x][v.y] = 1;
        for (int i = 0; i < 8; i++)
                if ((v.x + d[i].x >= 0 && v.y + d[i].y >= 0)
                && !(ma[v.x + d[i].x][v.y + d[i].y] == 1))
                        dfs(Point(v.x + d[i].x, v.y + d[i].y));
}

void Less(int i, int j, int ll) {
        ld kof = g[i][ll] / g[j][ll];
        for (int k = ll; k < l; k++)
                g[i][k] -= g[j][k] * kof;
        ans[i] -= ans[j] * kof;
}

int main() {
        cin >> n >> m;
        for (i = 0; i < n; i++)
                for (j = 0; j < m; j++) {
                        cin  >> ch;
                        ma[i][j] = (ch == '#');
                        if (ch == 'M')
                                start = Point(i, j);
                        if (ch == 'C')
                                ma[i][j] = -1;
                }

        dfs(start);
        dans = 0;
        for (i = 0; i < n; i++)
                for (j = 0; j < m; j++)
                                dans += (vis[i][j] && ma[i][j] == -1);
        if (dans == 0) {
                cout << "-1";
                return 0;
        }

        k = 1, l = 1;
        for (i = 0; i < n; i++)
                for (j = 0; j < m; j++)
                        if (vis[i][j]) {
                                if (ma[i][j] == -1)
                                        continue;
                                if (num[i][j] == 0)
                                        num[i][j] = l, l++;

                                dans = 1;
                                for (int p = 0; p < 8; p++)
                                        if (vis[i + d[p].x][j + d[p].y]) {
                                                dans++;
                                                if (ma[i + d[p].x][j + d[p].y] == -1)
                                                        continue;
                                                if (num[i + d[p].x][j + d[p].y] == 0)
                                                        num[i + d[p].x][j + d[p].y] = l, l++;
                                                g[k][num[i + d[p].x][j + d[p].y]] = -1;
                                        }
                                g[k][num[i][j]] = dans - 1;
                                ans[k] = dans;
                                ind[k] = k;
                                k++;
                        }

        for (i = 1; i < l; i++)
                ind[i] = i;

        for (i = 1; i < l; i++) {
                mx = 0;
                for (j = i; j < l; j++)
                        if (fabs(g[ind[j]][i]) > mx) {
                                mx = fabs(g[ind[j]][i]);
                                r = j;
                        }
                swap(ind[r], ind[i]);
                for (j = 1; j < k; j++)
                        if (i != j && fabs(g[ind[j]][i]) > eps)
                                Less(ind[j], ind[i], i);
        }

        i = num[start.x][start.y];
        cout.precision(20);
        if (g[ind[i]][i] < eps)
                cout << "=(";
        cout << ans[ind[i]] / g[ind[i]][i];
//      cin >> n;
}