#include <bits/stdc++.h>   using namespace std;   int main(int argc, char const *argv[]) {     int d, n, c, ans, m;     string arr[105];     cin >> n >> d;     ans = 0;     m = 0;     for (int i = 0; i < d; i++) {       cin >> arr[i];       c = 0;       for (int j = 0; j < n; j++) {         if (arr[i][j] ==  1 ) c++;       }       if (c < n)         m++;       else         m = 0;       if (m > ans) ans = m;     }     cout << ans << endl;     return 0;   }   