#include <bits/stdc++.h>
#define int long long
const int N = 1e6 + 10, MOD = 1e9 + 10;
using namespace std;
signed main() {
	int a, b, c;
	cin >> a >> b >> c;
	printf("%.3f", max({a, b, c}) * 1.0 / (max({a, b, c})*max({a, b, b + c})));
	return 0;
}