#include <bits/stdc++.h>
using namespace std;
long long binsearch(long long n, long long m, long long k) {
  long long low = 1, high = n * m + 1, mid;
  while (low < high) {
    mid = (low + high) >> 1;
    long long x = 0;
    for (long long i = 1; i <= n; i++) {
      x += min(m, mid / i);
    }
    if (x >= k)
      high = mid;
    else
      low = mid + 1;
  }
  return low;
}
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  cout << binsearch(n, m, k);
  return 0;
}
