#include <bits/stdc++.h>
using namespace std;
int max(int x, int y, int z)
{
    if (x > y && x > z)
        return x;
    if (y > z)
        return y;
    return z;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int a, b, c;
    double m;
    cin >> a >> b >> c;
    m = max(a, b, c) / ((double)max(a + b, b, c) * max(a, b, b + c));
    cout << fixed << setprecision(3) << m << "\n";
    return 0;
}