#include <stdio.h>

int main () {
  int n = 0;
  int m = 0;
  char s[257] = "";
  
  int res = 0;
  
  int v[256] = {};
  int cnt[4] = {};
  
  res = scanf("%d", &n);
  res = scanf("%d", &m);
  for (int i = 0; i < m; i++) {
    res = scanf("%s", s);
    for (int j = 0; j < n; j++) {
      v[j] |= (1<<((int)(s[j]-'0')));
    }
  }
  
  for (int i = 0; i < n; i++) {
    cnt[v[i]]++;
  }
  
  if (cnt[1] > 1 || cnt[2] > 1) {
    printf("No\n");
  } else {
    printf("Yes\n");
  }
  
  return 0;
}