#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, k;
  while (scanf("%I64d%I64d%I64d", &n, &m, &k) > 0) {
    long long low = 1, high = n * m + 1, sum, ans;
    while (low < high) {
      long long tmp, mid = (low + high) / 2;
      sum = 0;
      for (int i = 1; i <= n; i++) {
        tmp = mid / i;
        if (tmp == 0) break;
        sum += min(tmp, m);
      }
      if (sum >= k)
        high = mid;
      else
        low = mid + 1;
    }
    printf("%I64d\n", low);
  }
}
