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#include <cstdio>
#include <cassert>
#include <cstring>
#include <cstdint>
#include <algorithm>
#include <string>
#include <cstdlib>
#include <ctime>
#include <vector>

using namespace std;

const int max_size = 10;

char t[max_size][max_size];

int n, m;
int k;

unsigned long long move_done;
unsigned long long final_pos_done;

unsigned long long final_pos;
unsigned long long cur_pos;

int g_mv_cnt;

bool in_final_pos()
{
//	return (p.x == final_pos.x) && (p.y == final_pos.y);
	return (cur_pos == final_pos);
}

class pion {
public:
	int nr;
	int x;
	int y;

	bool mv1; // x-1
	bool mv2; // x+1
	bool mv3; // y-1
	bool mv4; // y+1
	int  mv_cnt;

	pion(int _nr, int _x, int _y) { nr = _nr; x = _x; y = _y; mv_cnt = 0; }
	void print();
	void set_moves();
	void do_move(int nr);
};

void update_cur_pos(const pion *p)
{
   	cur_pos += (8*(p->x-1)+p->y-1) << p->nr*8;
}

vector<pion> pi;

void pion::print()
{
	printf("x=%d, y=%d, (%d, %d, %d, %d), %d\n", x, y, mv1 ? 1 : 0, mv2 ? 1 : 0, mv3 ? 1 : 0, mv4 ? 1 : 0, mv_cnt);
}

bool is_free(int x, int y)
{
	for(int i = 0; i < pi.size(); ++i) {
		if (pi[i].x == x && pi[i].y == y) {
			return false;
		}
	}
	return true;
}

void pion::set_moves()
{
	g_mv_cnt -= mv_cnt;
	mv1 = (x > 0 && is_free(x-1, y));
	mv2 = (x < n-1 && is_free(x+1,y));
	mv3 = (y > 0 && is_free(x, y-1));
	mv4 = (y < m-1 && is_free(x,y+1));
	mv_cnt = (mv1 ? 1 : 0) + (mv2 ? 1 : 0) + (mv3 ? 1 : 0) + (mv4 ? 1 : 0);
	g_mv_cnt += mv_cnt;
}

void update_pions_moves(int nr, int x, int y)
{
	for(int i = 0; i < pi.size(); ++i) {
		if (i != nr) {
			if (pi[i].x == x && (pi[i].y-1 == y || pi[i].y+1 == y)) pi[i].set_moves();
			if (pi[i].y == y && (pi[i].x-1 == x || pi[i].x+1 == x)) pi[i].set_moves();
		}
	}
}

void pion::do_move(int move_nr)
{
   	cur_pos -= (8*(x-1)+y-1) << nr*8;
	update_pions_moves(nr,x,y);
	if (mv1) {
		if (move_nr == 0) { --x; this->set_moves(); update_pions_moves(nr,x,y); update_cur_pos(this); return; }
		--move_nr;
	}
	if (mv2) {
		if (move_nr == 0) { ++x; this->set_moves(); update_pions_moves(nr,x,y); update_cur_pos(this); return; }
		--move_nr;
	}
	if (mv3) {
		if (move_nr == 0) { --y; this->set_moves(); update_pions_moves(nr,x,y); update_cur_pos(this); return; }
		--move_nr;
	}
	assert(mv4);
	assert(move_nr == 0);
	++y;
	this->set_moves();
	update_pions_moves(nr,x,y);
	update_cur_pos(this);
}

void calc_initial_moves()
{
	for(int i = 0; i < pi.size(); ++i) {
		pi[i].set_moves();
	}
}


void do_calc()
{
	int rand_nr;
	int i;
	
	calc_initial_moves();
//	pi[0].print();

	while (1) {
//		pi[0].print();
		i = 0;
		rand_nr = rand() % g_mv_cnt;
//		printf("global mv cnt = %d, rand_nr = %d\n", g_mv_cnt, rand_nr);
		while( pi[i].mv_cnt <= rand_nr ) {
			rand_nr -= pi[i].mv_cnt;
			++i;

		}
		pi[i].do_move(rand_nr);
		++move_done;

//		if (in_final_pos(p1)) {
//			++final_pos_done;
//		}

		if (move_done % 10 == 0) {
			if (in_final_pos()) {
				++final_pos_done;
			}
		}

		if (move_done % 10000000 == 0) {
//			printf("%llu/ %llu = %.15f\n", final_pos_done, move_done, 10.0 * ((long double) final_pos_done)/((long double) move_done));
			printf("%Lf\n", 10.0 * ((long double) final_pos_done)/((long double) move_done));
			return;
		}
	}

}

int main()
{
	char s[max_size];

	srand(time(NULL));
        scanf("%d %d\n", &n, &m);
	for(int i = 0; i < n; ++i) {
		scanf("%s\n", s);
		for(int j = 0; j < m; ++j) {
			if (s[j] == 'O') {
				pi.push_back( pion(k, i, j) );
				cur_pos += (8*(i-1)+j-1) << k*8;
				++k;
			}
		}
	}
	k = 0;
	for(int i = 0; i < n; ++i) {
		scanf("%s\n", s);
		for(int j = 0; j < m; ++j) {
			if (s[j] == 'O') {
				final_pos += (8*(i-1)+j-1) << k*8 ;
				++k;
			}
		}
	}

	do_calc();

        return 0;
}