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