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// Wiktor Cupiał
// TU Delft
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
#define mp make_pair
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define eb emplace_back
#define st first
#define nd second
#define vt vector
#define VAR(__var)  #__var << ": " << __var << " "
#define PAIR(__var) #__var << ": " << __var.first << ", " << __var.second << " "
#define FOR(__var, __start, __end)  for(int __var=__start; __var<__end; ++__var)
#define FORB(__var, __start, __end) for(int __var=__start; __var>__end; --__var)
#define maxi(__x, __y) __x = (__x>__y?__x:__y)
#define mini(__x, __y) __x = (__x<__y?__x:__y)
#define all(__var)     (__var).begin(),(__var).end()
#define rall(__var)    (__var).rbegin(),(__var).rend()
#define sz(__var)      (int)(__var).size()
#define satori         int __test; cin>>__test; while(__test--)
 
#ifndef DEBUG
#define DEBUG 0
#endif
#define debug if(DEBUG)
 
using namespace std;
 
using namespace __gnu_pbds;
template <typename T>
using ord_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
 
// templeos <3
typedef     int16_t i16;
typedef     int32_t i32;
typedef     int64_t i64;
typedef        void  u0;
typedef        bool  u1;
typedef        char  u8;
typedef    uint16_t u16;
typedef    uint32_t u32;
typedef    uint64_t u64;
typedef       float f32;
typedef      double f64;
typedef long double f86;
 
typedef       long long ll;
typedef     long double ld;
typedef   pair<ll, ll> pll;
typedef pair<int, int> pii;
 
const int INF = 1e9+2137;

typedef pair<vt<int>, int> stan;

int conv(int x, int y) {
	return x*10+y;
}

pii re_conv(int x) {
	return {x/10, x%10};
}

int32_t main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

	int n, m;
	cin >> n >> m;
	
	vt<int> start(8, INF), target(8, INF);
	int now = 0;
	FOR(i, 0, n) 
		FOR(j, 0, m) {
			char x;
			cin >> x;
			if(x == 'O')
				start[now++] = conv(i, j);
		}

	now = 0;
	FOR(i, 0, n) 
		FOR(j, 0, m) {
			char x;
			cin >> x;
			if(x == 'O')
				target[now++] = conv(i, j);
		}

	sort(all(start));
	sort(all(target));
	vt<int> dx = {1,-1,0,0};
	vt<int> dy = {0,0,1,-1};
	
	map<stan, int> vis;
	queue<stan> q;
	q.push({start, 0});
	vis[{start, 0}] = 1;

	int dobre = 0;
	int ile = 0;
	while(sz(q)) {
		auto [v, d] = q.front();
		q.pop();

		/*
		cout << "----\n";
		for(auto x : v)
			cout << x << ' ';
		cout << '\n' << d << '\n';
		cout << "----\n";
		*/

		FOR(i, 0, 8) {
			if(v[i] == INF)
				break;
			auto [a, b] = re_conv(v[i]);
			FOR(j, 0, 4) {
				int x = a+dx[j];
				int y = b+dy[j];
				if(x < 0 || y < 0 || x >= n || y >= m)
					continue;
				int cnow = conv(x, y);
				bool ok = true;
				FOR(k, 0, 8)
					if(v[k] == cnow) {
						ok = false;
						break;
					}
				if(!ok)
					continue;
				vt<int> tmp = v;
				tmp[i] = cnow;
				sort(all(tmp));
				// if((d^1) == 0 && !vis.count({tmp, d^1})) 
				if((d^1) == 0) {
					++ile;
					if(tmp == target)
						++dobre;
				}
				if(!vis.count({tmp, d^1})) {
					q.push({tmp, d^1});
					vis[{tmp, d^1}] = 1;
				}
			}
		}
	}

	cout << setprecision(15) << fixed << (ld)dobre/(ld)ile << '\n';

	return 0;
}