#include <bits/stdc++.h>
using namespace std;
long long int m, n, k;
long long int countless(long long int x) {
  long long int cnt = 0, i;
  for (i = 1; i <= n; i++) {
    cnt += min((x - 1) / i, m);
  }
  return cnt;
}
long long int binarysearch() {
  long long int l = 1, r = n * m, mid, ans = -1, t;
  while (l <= r) {
    mid = (l + r) / 2;
    t = countless(mid);
    if (t < k) {
      ans = mid;
      l = mid + 1;
    } else {
      r = mid - 1;
    }
  }
  return ans;
}
int main() {
  std::ios_base::sync_with_stdio(0);
  long long int i, j, l, p;
  cin >> n >> m >> k;
  cout << binarysearch();
}
