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#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using db = double;
using ull = unsigned long long;
 
using pi = pair<int, int>;
using pl = pair<ll, ll>;
 
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pi>;
using vpl = vector<pl>;
 
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define f first
#define s second
 
#define tcT template<class T
#define tcTU tcT, class U
 
#define sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define rep(i,a,b) for(int i = (a); i < (b); i++)
#define rrep(i,a,b) for(int i = (b) - 1; i >= (a); i--)
 
const db PI = acos(-1);
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
 
tcT> bool ckmin(T& a, const T& b) { return b < a ? a=b, 1 : 0; }
tcT> bool ckmax(T& a, const T& b) { return a < b ? a=b, 1 : 0; }
 
tcT> void _dbg(const char *sdbg, T h){ cerr<<sdbg<<'='<<h<<endl; }
tcT, class... TA> void _dbg(const char *sdbg, T h, TA... a) {
	while(*sdbg!=',') cerr<<*sdbg++;
	cerr<<'='<<h<<','; _dbg(sdbg+1, a...);
}
 
tcT> ostream &operator<<(ostream& os, vector<T> V) {
	os << "["; for (auto vv : V) os << vv << ","; return os << "]";
}
tcT, class V> ostream &operator<<(ostream &os, pair<T,V> P) {
	return os << "(" << P.f << "," << P.s << ")";
}
 
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (__VA_ARGS__)
#define cerr if(0)cout
#endif

using frac_int = ll;
struct frac_t {
	frac_int a, b;

	frac_t(frac_int _a, frac_int _b) : a(_a), b(_b) {
		assert (b != 0);
		frac_int d = __gcd(a, b);
		a /= d;
		b /= d;
	}
	frac_t(frac_int _a) : a(_a), b(1) {}
	frac_t() : a(0), b(1) {}

	frac_t operator+(const frac_t &other) const {
		return frac_t(a*other.b + other.a*b, other.b * b);
	}

	frac_t operator-(const frac_t &other) const {
		return frac_t(a*other.b - other.a*b, other.b * b);
	}

	frac_t operator*(const frac_t &other) const {
		return frac_t(a*other.a, b*other.b);
	}

	frac_t operator/(const frac_t &other) const {
		assert (other.a != 0);
		return frac_t(a*other.b, b*other.a);
	}

	bool operator<(const frac_t &other) const {
		return a*other.b < b*other.a;
	}

	bool operator>(const frac_t &other) const {
		return a*other.b > b*other.a;
	}

	bool operator==(const frac_t &other) const {
		return a*other.b == b*other.a;
	}

	bool operator!=(const frac_t &other) const {
		return !(*this == other);
	}
};

ostream& operator<<(ostream &os, const frac_t &frac) {
	return os << frac.a << "/" << frac.b;
}

int n, m;
const int MAXN = 202;

string s[MAXN];
frac_t alive[MAXN][MAXN];
ll deg[MAXN][MAXN];

constexpr pi moves[] = {{-1, 0}, {1, 0}, {0, 1}, {0, -1}};

// boundaries excluded
frac_t simulate(int x0, int y0, int x1, int y1) {
	rep(i,x0,x1) {
		rep(j,y0,y1) {
			if (s[i][j] == 'O') {
				alive[i][j] = 1;
			}
			else {
				alive[i][j] = 0;
			}
		}
	}

	auto valid = [&](int i, int j) -> bool {
		return x0 <= i && i < x1 && y0 <= j && j < y1;
	};

	// wykonuje się max 11 razy
	while (true) {
		frac_t time = 2;

		rep(i,x0,x1) {
			rep(j,y0,y1) {
				if (alive[i][j] == 0) continue;

				deg[i][j] = 0;

				for (pi mv : moves) {
					int nxti = i + mv.f;
					int nxtj = j + mv.s;

					if (!valid(nxti, nxtj)) continue;

					if (alive[nxti][nxtj] != 0) {
						deg[i][j]++;
					}
				}

				if (deg[i][j] == 0) continue;
				ckmin(time, alive[i][j] / deg[i][j]);
			}
		}

		if (time == 2) break;

		rep(i,x0,x1) {
			rep(j,y0,y1) {
				if (alive[i][j] == 0) continue;
				alive[i][j] = alive[i][j] - time * deg[i][j];
			};
		}
	}

	frac_t res = 0;

	rep(i,x0,x1) {
		rep(j,y0,y1) {
			res = res + alive[i][j];
		}
	}

	return res;
}

signed main() {
	ios_base::sync_with_stdio(false); cin.tie(nullptr);

	cin >> n >> m;

	rep(i,0,n) cin >> s[i];

	vpi question_marks;

	rep(i,0,n) {
		rep(j,0,m) {
			if (s[i][j] == '?') {
				question_marks.eb(i, j);
			}
		}
	}

	frac_t res = 0;

	rep(mask,0,(1<<sz(question_marks))) {
		rep(i,0,sz(question_marks)) {
			s[question_marks[i].f][question_marks[i].s] = ((mask & (1 << i)) ? 'O' : '.');
		}

		res = res + simulate(0,0,n,m);
	}

	res = res / frac_t((1 << sz(question_marks)));

	cout << res << "\n";

	return 0;
}