#include <bits/stdc++.h> using namespace std; int main() { int n,m; cin>>n>>m; int a[n][m]; int flag = 0; 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) { flag++; } } } if(flag == n * m) { cout<<"Yes"; } else { cout<<"No"; } return 0; }