#include <bits/stdc++.h>
using namespace std;
long long int t, n, m, a, b, x, k, y, q, M = 1e9 + 7;
float ans(long long int sum, long long int n) { return (float)sum / (float)n; }
long long int cntless(long long int x) {
  long long int ans = 0;
  for (long long int i = 1; i <= n; i++) {
    ans += (min((x - 1) / i, m));
  }
  return ans;
}
int main() {
  cin >> n >> m >> k;
  long long int f = 1, b = n * m, p, l, i;
  while (f < b) {
    long long int l = 0;
    p = (f + b) / 2;
    for (i = 1; i <= n; i++) l += min(m, p / i);
    if (l >= k)
      b = p;
    else
      f = p + 1;
  }
  cout << f << endl;
}
