#include <stdio.h>

int main () {
  int n = 0;
  int m = 0;
  char s[257] = "";
  
  int res = 0;
  
  long long v[256][1100] = {};
  int is_ok = 1;
  
  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++) {
      if (s[j] == '1') {
        v[j][i/60] |= (1LL<<((long long)(i%60)));
      }
    }
  }
  
  for (int i = 1; i < n; i++) {
    for (int j = 0; j < i; j++) {
      int tmp_ok = 0;
      for (int k = 0; k <= (m-1)/60; k++) {
        if (v[i][k] != v[j][k]) {
          tmp_ok = 1;
        }
      }
      is_ok *= tmp_ok;
    }
  }
  
  if (is_ok > 0) {
    printf("Yes\n");
  } else {
    printf("No\n");
  }
  
  return 0;
}