//include
//--------------------------------------------------
#include<vector>
#include<list>
#include<map>
#include<set>
#include<deque>
#include<stack>
#include<bitset>
#include<algorithm>
#include<functional>
#include<numeric>
#include<utility>
#include<sstream>
#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cctype>
#include<string>
#include<cstring>
#include<ctime>

using namespace std;

//conversion
//--------------------------------------------------
inline int toInt(const string &s){
    int v;istringstream sin(s);sin>>v;
    return v;
}
template<class T> inline string toString(T x){
    ostringstream sout;sout<<x;
    return sout.str();
}

//math
//--------------------------------------------------
template<class T> inline T sqr(T x){return x*x;}

//typedef
//--------------------------------------------------
typedef vector<int>VI;
typedef vector<VI>VVI;
typedef vector<string>VS;
typedef pair<int,int>PII;
typedef long long LL;

//container util
//--------------------------------------------------
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin())i=(c).begin();i!=(c).end();i++)
#define EXIST(s) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//--------------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

//constant
//--------------------------------------------------
const int INF=1e9+7;
const int dx[]={0,-1,0,1};
const int dy[]={-1,0,1,0};

//clear memory
#define CLR(a) memset((a),0,sizeof(a))

//debug
#define dump(x) cerr<<#x<<" = "<<(x)<<endl
#define debug(x) cerr<<#x<<" = "<<(x)<<"(L"<<__LINE__<<")"<<endl

//---------------------------------------------------



class State{
public:
    int x,y;
    bool p[24];
    State(){
        fill(p,p+24,false);
    }
    bool operator<(const State &s)const{
        if(x!=s.x)return x<s.x;
        if(y!=s.y)return y<s.y;
        REP(i,24)if(p[i]!=s.p[i])return p[i]<s.p[i];
        return false;
    }
};

int H,W;
int fld[10][10];


int solve(){
    int cnt=1;
    int sx,sy;
    REP(i,H)REP(j,W){
        if(fld[i][j]==1){
            fld[i][j]=cnt;
            cnt++;
        }
        else if(fld[i][j]==0)fld[i][j]=-1;
        else{
            fld[i][j]=0;
            sx=j;sy=i;
        }
    }

    map<State,int>prev;
    State s;s.x=sx;s.y=sy;
    prev[s]=1;

    REP(i,cnt){
        map<State,int>next;
        EACH(it,prev){
            REP(j,4){
                int nx=(*it).first.x;
                int ny=(*it).first.y;
                while(true){
                    nx+=dx[j];
                    ny+=dy[j];
                    if(nx<0||nx>=W||ny<0||ny>=H)break;
                    if(fld[ny][nx]==-1||(i!=cnt-1&&fld[ny][nx]==0))continue;

                    if(fld[ny][nx]!=0||(fld[ny][nx]==0&&i==cnt-1)){
                        State now=it->first;
                        int p=fld[ny][nx];
                        if(now.p[p])continue;
                        now.p[p]=true;
                        now.x=nx;
                        now.y=ny;
                        next[now]+=it->second;
                        break;
                    }
                }
            }
        }
        prev=next;
    }

    State gol;
    gol.x=sx;gol.y=sy;
    REP(i,cnt)gol.p[i]=true;
    return prev[gol];

}


int main(){
    while(cin>>W>>H,H||W){
        REP(i,H)REP(j,W)cin>>fld[i][j];
        cout<<solve()<<endl;
    }

    return 0;
}

Measured memory_bytes: 30664