#include <bits/stdc++.h>
using namespace std;
const int N = 10010;
long long n, m, k;
bool check(long long mid) {
  long long ans = 0;
  for (long long i = 1; i <= n; i++) ans = ans + min(m, mid / i);
  return ans >= k;
}
int main() {
  scanf("%lld%lld%lld", &n, &m, &k);
  long long l = 0, r = n * m, ans;
  while (l <= r) {
    long long mid = (l + r) >> 1;
    if (check(mid)) {
      ans = mid;
      r = mid - 1;
    } else
      l = mid + 1;
  }
  printf("%lld\n", ans);
  return 0;
}
