#include <cstdio>#include <cstring>int maze[12][12];bool tab[12][12];int n,m;typedef struct{ int x,y;}point;typedef struct{ int front;int rear;point data[100];}queue;queue q;void enque(int x,int y){point e;e.x=x,e.y=y; q.data[q.rear++]=e;tab[x][y]=false;}int deque(){ return q.front++;}int fun(int x,int y){ if(x+1<n&&tab[x+1][y]){ if(maze[x][y]+maze[x+1][y]) enque(x+1,y); else return 0;} if(y+1<m&&tab[x][y+1]){ if(maze[x][y]+maze[x][y+1]) enque(x,y+1); else return 0;}return 1;}int main(){ int i,j,anw,flag,pre; while(scanf("%d%d",&n,&m)!=EOF&&(m||n)) {anw=0;for(i=0;i<n;i++) for(j=0;j<m;j++) { scanf("%d",&maze[i][j]); anw+=maze[i][j]; } if(anw==n*m){ printf("Non"); continue;} q.front=q.rear=0; memset(tab,true,sizeof(tab)); tab[0][0]=false; enque(0,0);flag=0; while(q.rear!=q.front){ pre=deque();if(fun(q.data[pre].x,q.data[pre].y)==0){flag=1;break;}}if(flag) printf("Non");else printf("Yesn"); }return 0;}
