#include <bits/stdc++.h>
using namespace std;
int main() {
  string temporary;
  int swit, lamp;
  cin >> swit >> lamp;
  int first[2000] = {0};
  for (int i = 0; i < swit; i++) {
    cin >> temporary;
    for (int j = 0; j < temporary.length(); j++) {
      if (temporary[j] == '1') first[j] += 1;
    }
  }
  cin.clear();
  cin.seekg(0, cin.beg);
  cin >> swit >> lamp;
  int second[2000] = {0};
  memcpy(second, first, sizeof(second));
  for (int i = 0; i < swit; i++) {
    cin >> temporary;
    for (int j = 0; j < temporary.length(); j++) {
      if (temporary[j] == '1') second[j] -= 1;
    }
    int k = 0;
    for (int j = 0; j < temporary.length(); j++) {
      if (second[j] > 0) {
        k++;
      }
      if (k == lamp) {
        cout << "YES";
        return 0;
      }
    }
    memcpy(second, first, sizeof(second));
  }
  cout << "NO";
  return 0;
}
