#include <bits/stdc++.h>
using namespace std;
long long L, R, k, n, m;
int main() {
  scanf("%I64d%I64d%I64d", &n, &m, &k);
  L = 0;
  R = 1LL * n * m;
  while (L < R) {
    long long Mid = (L + R) >> 1, cnt = 0;
    for (int i = 1; i <= n; i++) cnt += min(m, Mid / i);
    if (cnt < k)
      L = Mid + 1;
    else
      R = Mid;
  }
  printf("%I64d\n", R);
}
