#include <bits/stdc++.h>
using namespace std;
template <typename T>
T trace2(T a, T b) {
  cerr << a << " " << b << '\n';
}
template <typename T>
T trace3(T a, T b, T c) {
  cerr << a << " " << b << " " << c << '\n';
}
template <typename T>
T trace4(T a, T b, T c, T d) {
  cerr << a << " " << b << " " << c << " " << d << '\n';
}
template <typename T>
T trace5(T a, T b, T c, T d, T e) {
  cerr << a << " " << b << " " << c << " " << d << " " << e << '\n';
}
template <typename T>
T trace6(T a, T b, T c, T d, T e, T f) {
  cerr << a << " " << b << " " << c << " " << d << " " << e << " " << f << '\n';
}
void err(istream_iterator<string> it) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
  cerr << *it << " = " << a << '\n';
  err(++it, args...);
}
template <typename T>
T pow(T a, T b, long long int m) {
  T ans = 1;
  while (b > 0) {
    if (b % 2 == 1) ans = (ans * a) % m;
    b /= 2;
    a = (a * a) % m;
  }
  return ans % m;
}
void swap(long long int *a, long long int *b) {
  long long int temp = *a;
  *a = *b;
  *b = temp;
  return;
}
long long int n, m, k;
long long int ans = 0;
bool check(long long int x) {
  long long int temp = 0;
  for (long long int i = 1; i <= n; i++) {
    temp += min((x - 1) / i, m);
  }
  if (temp < k) {
    return true;
  }
  return false;
}
void search(long long int hi, long long int lo) {
  while (lo <= hi) {
    long long int mid = lo + (hi - lo) / 2;
    if (check(mid)) {
      ans = max(ans, mid);
      lo = mid + 1;
    } else {
      hi = mid - 1;
    }
  }
}
void fuck() {
  cin >> n >> m >> k;
  search(n * m, 1);
  cout << ans << '\n';
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  fuck();
  return 0;
}
