#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long check(long long x) {
  long long sum = 0;
  for (int i = 1; i <= n; i++) {
    sum += min(x / i, m);
  }
  return sum;
}
int main() {
  while (scanf("%I64d %I64d %I64d", &n, &m, &k) == 3) {
    long long L = 1, R = n * m;
    while (L < R) {
      long long mid = (L + R) >> 1;
      if (check(mid) >= k)
        R = mid;
      else
        L = mid + 1;
    }
    printf("%I64d\n", R);
  }
}
