3669. Diplomas

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define mp make_pair
#define pb push_back

const long double eps = 1e-7;

int w,h,n;

bool F(int t)
{
    return (t/w)*(t/h) >= n;
}

signed main() {
    ios::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);

    cin >> w >> h >> n;

    int L = 0,R=max(w,h)*n;
    int mid;

    while(R-L>1)
    {
        mid = (L+R)/2;
        if(F(mid))
            R = mid;
        else
            L = mid;
    }

    cout << (F(L) ? L : R);

    return 0;
}