#include<bits/stdc++.h> using namespace std; int main() { int a[20][20],m,n; bool f=true; cin>>n>>m; for(int i=0;i<n;i++){ for(int j=0;j<m;j++){ cin>>a[i][j]; if(a[i][j]!=0&&a[i][j]!=1){ f=false; } } } if(f==true){ cout<<"Yes"<<endl; }else{ cout<<"No"<<endl; } return 0; } /************************************************************** Problem: 1828 User: admin Language: C++ Result: Accepted Time:20 ms Memory:2072 kb ****************************************************************/