#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
  ll N,M;
  cin>>N>>M;
  vector<ll> A(N);
  for(int i=0;i<M;i++)for(int j=0;j<N;j++){
    char zeon;
    cin>>zeon;
    if(zeon=='1') A[j]++;
  }
  bool ye=true;
  for(int i=0;i<N;i++)for(int j=i+1;j<N;j++){
    if(A[i]==A[j]) ye=false;
  }
  if(ye) cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
}