#include <bits/stdc++.h>
using namespace std;
long long n, m, k, l, r, mid, ans;
int work(long long x) {
  long long nowans = 0;
  for (int i = 1; i <= n; i++) nowans += min(x / i, m);
  return nowans >= k;
}
int main() {
  scanf("%I64d%I64d%I64d", &n, &m, &k);
  l = 1;
  r = n * m;
  while (l <= r) {
    mid = l + r >> 1ll;
    if (work(mid))
      r = mid - 1, ans = mid;
    else
      l = mid + 1;
  }
  printf("%I64d", ans);
}
