#include<stdio.h>
#include<map>

int map[11][11],houseCount,rootCount,gy,gx;
int dxs[]={1,0,-1,0};
int dys[]={0,1,0,-1};
int houseMap[11][11];
int w,h;

struct root{
	int memo,nowP;//memoは訪れた家を1bit単位で管理する
	bool operator<(const root r)const{
		if(memo!=r.memo) return memo<r.memo;
		return nowP<r.nowP;
	}
};

std::map<root,int> memos;




int saiki(int sx,int sy,int deep,int memo){
	if(deep==houseCount){
		return 1;
	}

	int c;

	if(deep==houseCount-1){
		c=2;
	}else{
		c=1;
	}
	int nx,ny,sum=0;
	root r;
	r.memo=memo;
	for(int i=0;i<4;i++){
		for(int j=1;j<11;j++){
			nx=sx+dxs[i]*j;
			ny=sy+dys[i]*j;
			if(nx<0 || w<=nx || ny<0 || h<=ny) break;
			if(map[ny][nx]==c){
				r.nowP=houseMap[ny][nx];
				if(memos.find(r)==memos.end()){
					map[ny][nx]=-c;
					memos[r]=saiki(nx,ny,deep+1,memo|(1<<r.nowP));
					sum+=memos[r];
					map[ny][nx]=c;
				}else{
					sum+=memos[r];
				}
				break;
			}
		}
	}
	return sum;
}

void setData(){
	houseCount=rootCount=0;
	memos.clear();
	for(int i=0;i<h;i++){
		for(int j=0;j<w;j++){
			scanf("%d",&map[i][j]);
			if(map[i][j]==1){
				houseMap[i][j]=houseCount;
				houseCount++;
			}else if(map[i][j]==2){
				houseMap[i][j]=houseCount;
				houseCount++;
				gx=j;
				gy=i;
			}
		}
	}
	printf("%d\n",saiki(gx,gy,0,0));
}

int main(){
	scanf("%d %d",&w,&h);
	while(w!=0 && h!=0){
		setData();
		scanf("%d %d",&w,&h);
	}
}