#include <cstdio>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <ctime>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <set>
#include <map>
#include <iostream>
#include <deque>
#include <complex>
#include <string>
#include <iomanip>
#include <sstream>
#include <bitset>
#include <valarray>
#include <unordered_map>
#include <iterator>
#include <functional>
#include <cassert>
using namespace std;
typedef long long int ll;
typedef unsigned int uint;
typedef unsigned char uchar;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define REP(i,x) for(int i=0;i<(int)(x);i++)
#define REPS(i,x) for(int i=1;i<=(int)(x);i++)
#define RREP(i,x) for(int i=((int)(x)-1);i>=0;i--)
#define RREPS(i,x) for(int i=((int)(x));i>0;i--)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();i++)
#define RFOR(i,c) for(__typeof((c).rbegin())i=(c).rbegin();i!=(c).rend();i++)
#define ALL(container) (container).begin(), (container).end()
#define RALL(container) (container).rbegin(), (container).rend()
#define SZ(container) ((int)container.size())
#define mp(a,b) make_pair(a, b)
#define pb push_back
#define eb emplace_back
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"["; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"]"; return os;
}
template<class T> ostream& operator<<(ostream &os, const set<T> &t) {
os<<"{"; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"}"; return os;
}
template<class S, class T> ostream& operator<<(ostream &os, const map<S, T> &t) {
os<<"{"; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"}"; return os;
}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
template<class S, class T> pair<S,T> operator+(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first+t.first, s.second+t.second);}
template<class S, class T> pair<S,T> operator-(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first-t.first, s.second-t.second);}

const int INF = 1<<28;
const double EPS = 1e-8;
const int MOD = 1000000007;

typedef unordered_map<int, int> Array;
typedef vector<Array> Matrix;
ostream& operator<<(ostream &os, const Array &t) {
os<<"["; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"]"; return os;
}
ostream& operator<<(ostream &os, const Matrix &t) {
FOR(it,t)os<<*it<<endl;return os;
}

int T, n, m;

inline ll mod_inv(ll a, ll m){
  ll b = m, u = 1, v = 0;
  while (b) {
    ll t = a / b;
    swap(a -= t * b, b);
    swap(u -= t * v, v);
  }
  return (u % m + m) % m;
}


int det(Matrix mat){
	int n = mat.size();
	ll ans = 1;
	REP(i, n){
		ans = ans * mat[i][i] % MOD;
		if(!ans) return ans;
		ll inv = mod_inv(mat[i][i], MOD);
		for(int j=i+1;j<n;j++)if(mat[j].count(i)){
			ll coef = (MOD - mat[j][i] * inv % MOD) % MOD;
			for(auto it : mat[i]){
				auto &jt = mat[j][it.first];
				jt = (jt + coef*it.second) % MOD;
				if(jt == 0) mat[j].erase(it.first);
			}
		}
	}
	return ans;
}

int main(int argc, char *argv[]){
	ios::sync_with_stdio(false);
	int T = 1;
	while(cin >> n >> m, n){
		vector<string> s(n);
		REP(i, n) cin >> s[i];
		vi to(n*m);
		int c = 0;
		Matrix mat;
		REP(i, n*m){
			int x = i%m;
			int y = i/m;
			if(s[y][x] == '#') continue;
			mat.eb();
			if(x && s[y][x-1] != '#'){
				mat[c][c] ++; mat[c-1][c-1] ++;
				mat[c][c-1] = mat[c-1][c] = MOD-1;
			}
			if(y && s[y-1][x] != '#'){
				mat[c][c] ++; mat[to[i-m]][to[i-m]] ++;
				mat[c][to[i-m]] = mat[to[i-m]][c] = MOD-1;
			}
			to[i] = c++;
		}
		REP(i, c-1) mat[i].erase(c-1);
		mat.pop_back();
		cout << "Case " << T++ << ": " << det(mat) << endl;
	}
	return 0;
}

Measured memory_bytes: 9312