#include <bits/stdc++.h>
using namespace std;
void solve();
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t = 1;
  while (t--) {
    solve();
    cout << "\n";
  }
  cerr << "time taken : " << (float)clock() / CLOCKS_PER_SEC << " secs" << endl;
  return 0;
}
long long num(long long x, long long n, long long m) {
  long long res = 0;
  --x;
  for (long long i = 1; i <= n; i++) res += min(x / i, m);
  return res;
}
void solve() {
  long long n, m;
  cin >> n >> m;
  long long k;
  cin >> k;
  long long l = 1;
  long long r = n * m + 1;
  while (l < r) {
    long long x = (l + r) >> 1;
    if (num(x, n, m) < k)
      l = x + 1;
    else
      r = x;
  }
  cout << l - 1;
  return;
}
