#include <bits/stdc++.h>
using namespace std;
const int maxn = 1000;
long long n, m, k, l, r, mid, ans;
bool ok(long long a) {
  long long sum = 0;
  for (int i = 1; i <= n; i++) {
    if (i * m <= a)
      sum += m;
    else
      sum += a / i;
  }
  if (sum >= k)
    return true;
  else
    return false;
}
int main() {
  cin >> n >> m >> k;
  l = 1;
  r = n * m;
  mid = (l + r) / 2;
  while (l <= r) {
    if (ok(mid)) {
      ans = mid;
      r = mid - 1;
    } else {
      l = mid + 1;
    }
    mid = (l + r) / 2;
  }
  cout << ans << endl;
  return 0;
}
