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