#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("O3")
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
using namespace std;
inline long long int read() {
  long long int x = 0;
  static long long int p;
  p = 1;
  static char c;
  c = getchar();
  while (!isdigit(c)) {
    if (c == '-') p = -1;
    c = getchar();
  }
  while (isdigit(c)) {
    x = (x << 1) + (x << 3) + (c - 48);
    c = getchar();
  }
  x *= p;
  return x;
}
long long int n, m, k;
bool is_ok(long long int mid) {
  long long int ans = 0;
  for (long long int i = 1; i < (long long int)n + 1; i++) {
    long long int temp = (mid) / i;
    temp = min(temp, m);
    ans += temp;
  }
  return ans >= k;
}
void solve(int tt);
int main() {
  int tt = 1;
  for (long long int i = 0; i < (long long int)tt; i++) solve(i + 1);
}
void solve(int tt) {
  n = read();
  m = read();
  k = read();
  long long int l = 0, r = 1e17;
  long long int ans = -1;
  while (l <= r) {
    long long int mid = (l + r) >> 1;
    if (is_ok(mid)) {
      ans = mid;
      r = mid - 1;
    } else
      l = mid + 1;
  }
  cout << ans << endl;
}
