#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool isLeap(T y) {
  return (y % 400 == 0) || (y % 100 ? y % 4 == 0 : false);
}
template <class T>
inline T gcd(T a, T b) {
  return (b) == 0 ? (a) : gcd((b), ((a) % (b)));
}
template <class T>
inline T lcm(T a, T b) {
  return ((a) / gcd((a), (b)) * (b));
}
template <class T>
inline T BigMod(T Base, T power, T M = 1000000007) {
  if (power == 0) return 1;
  if (power & 1)
    return ((Base % M) * (BigMod(Base, power - 1, M) % M)) % M;
  else {
    T y = BigMod(Base, power / 2, M) % M;
    return (y * y) % M;
  }
}
template <class T>
inline T ModInv(T A, T M = 1000000007) {
  return BigMod(A, M - 2, M);
}
int fx[] = {-1, +0, +1, +0, +1, +1, -1, -1, +0};
int fy[] = {+0, -1, +0, +1, +1, -1, +1, -1, +0};
int day[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  long long low = 1, high = 1e12, mid, save;
  while (low <= high) {
    mid = (low + high) >> 1;
    long long cnt = 0;
    for (int i = 1; i <= n; i++) {
      long long x = mid / i;
      if (mid % i == 0) x--;
      if (x > m) x = m;
      cnt += x;
    }
    if (cnt >= k) {
      save = mid;
      high = mid - 1;
    } else
      low = mid + 1;
  }
  long long mx = 0;
  for (int i = 1; i <= n; i++) {
    long long x = save;
    long long pnt = x / i;
    if (x % i == 0) pnt--;
    if (pnt > m) pnt = m;
    mx = max(mx, pnt * i);
  }
  cout << mx;
  return 0;
}
