#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <deque>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <bitset>
#include <functional>
#include <utility>
#include <algorithm>
#include <numeric>
#include <typeinfo>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <ctime>

using namespace std;

#define dump(n) cout<<"# "<<#n<<"="<<(n)<<endl
#define debug(n) cout<<__FILE__<<","<<__LINE__<<": #"<<#n<<"="<<(n)<<endl
#define repi(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,n) repi(i,0,n)
#define iter(c) __typeof((c).begin())
#define foreach(i,c) for(iter(c) i=(c).begin();i!=(c).end();i++)
#define allof(c) (c).begin(),(c).end()
#define mp make_pair

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int,int> pii;

int main()
{
	for(int w,h;cin>>w>>h,w|h;){
		vvi field(h,vi(w));
		rep(i,h) rep(j,w)
			cin>>field[i][j];
		
		vector<pii> homes;
		int counter=0;
		rep(i,h) rep(j,w){
			if(field[i][j]==1){
				field[i][j]=++counter;
				homes.push_back(mp(i,j));
			}
			else if(field[i][j]==2){
				field[i][j]=0;
				homes.insert(homes.begin(),mp(i,j));
			}
			else
				field[i][j]=-1;
		}
		
		map<pair<int,int>,int> m;
		m[mp(1,0)]=1;
		foreach(iter,m){
			m.erase(m.begin(),iter);
			
			int state=iter->first.first;
			int prev=iter->first.second;
			if(state==(1<<homes.size())-1)
				break;
			
			const int di[]={-1,1,0,0};
			const int dj[]={0,0,-1,1};
			rep(i,4){
				int pi=homes[prev].first,pj=homes[prev].second;
				for(;;){
					pi+=di[i];
					pj+=dj[i];
					if(pi<0 || h<=pi || pj<0 || w<=pj)
						break;
					int homei=field[pi][pj];
					if(homei>=1){
						if(state&(1<<homei))
							continue;
						else{
							m[mp(state|(1<<homei),homei)]+=iter->second;
							break;
						}
					}
				}
			}
		}
		int res=0;
		for(iter(m) iter=m.lower_bound(mp((1<<homes.size())-1,0));iter!=m.end();iter++){
			int prev=iter->first.second;
			int pi=homes[prev].first,pj=homes[prev].second;
			if(pi==homes[0].first || pj==homes[0].second)
				res+=iter->second;
		}
		cout<<res<<endl;
	}
	
	return 0;
}