//
// Created by lionell on 6/6/15.
//

#include <bits/stdc++.h>

using namespace std;

#ifndef ONLINE_JUDGE
#define cin in
ifstream in("/home/lionell/Developing/acm/codeforces/looksery_cup_2015/in.txt");
#endif

int main() {
    int a = 0, b = 0, c = 0, d = 0;
    cin >> a >> b >> c >> d;
    double l = 0.0, r = (double)max(max(a, b), max(c, d));
    while ()
    return 0;
}