#include <bits/stdc++.h>   using namespace std;   string s[555];   int dp[555], v[555], ones[555];   vector<pair<int, int> > vc[555];   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, m, k;     cin >> n >> m >> k;     for (int i = 1; i <= n; i++) {       cin >> s[i];       int cnt = 0;       for (int j = 0; j < m; j++) {         if (s[i][j] ==  1 ) ones[cnt++] = j + 1;       }       memset(v, 0, sizeof(v));       v[cnt] = m;       for (int j = 0; j < cnt; j++) {         for (int k = j; k < cnt; k++) {           int len = cnt - (k - j + 1);           int value = m - (ones[k] - ones[j] + 1);           v[len] = max(v[len], value);         }       }       for (int j = 0; j <= k; j++) {         if (v[j]) vc[i].push_back(make_pair(j, v[j]));       }     }     for (int i = 1; i <= n; i++) {       for (int j = k; j >= 0; j--) {         for (int k = 0; k < vc[i].size(); k++) {           if (j >= vc[i][k].first)             dp[j] = max(dp[j], dp[j - vc[i][k].first] + vc[i][k].second);         }       }     }     cout << n * m - dp[k] << endl;     return 0;   }   