#include <iostream>
using namespace std;
int main() {
    long long int w, h, n;
    cin >> w >> h >> n;
    long long int l = 0, r = n * max(w,h);
    while (l < r-1) {
        long long int x = (l+r)/2;
        long long int max_in = x / max(w,h);
        long long int min_in = (n-1) / max_in + 1;
        if (min(w,h) * min_in > x) {
            l = x;
        } else {
            r = x;
        }
    }
    cout << r;
    return 0;
}