#include <bits/stdc++.h>
using namespace std;
long long int get(long long int x, long long int n, long long int m) {
  long long int cnt = 0;
  for (__typeof(n + 1) i = 1 - (1 > n + 1); i != n + 1 - (1 > n + 1);
       i += 1 - 2 * (1 > n + 1))
    cnt += min(m, x / i);
  return cnt;
}
int main() {
  long long int n, m, k;
  scanf("%lld", &n);
  scanf("%lld", &m);
  scanf("%lld", &k);
  long long int lo = 1, hi = n * m;
  while (lo < hi) {
    long long int mid = (lo + hi) >> 1;
    long long int cnt = get(mid, n, m);
    if (cnt >= k)
      hi = mid;
    else
      lo = mid + 1;
  }
  printf("%lld\n", lo);
  return 0;
}
