function range(a,b) {
        let prd = a,i = a;
        while (i++< b) {
            prd*=i;
        }
        return prd;
    }
    function comb(n, r) {
        if (n==r || r==0) return 1;
        else {
            r=(r < n-r) ? n-r : r;
            return range(r+1, n)/range(1,n-r);
        }
    }
    let value = input.split(' ');
    let p = parseFloat(value[0])/(parseFloat(value[1]) + parseFloat(value[0]));
    let q = 1-p, b =[];
    for(let i = 3; i <= 6; i++) {
        let f = comb(6, i) * Math.pow(p, i) * Math.pow(q, (6 - i));
        b.push(f);
    }
    console.log((b.reduce((sum, a) => sum + a, 0)).toFixed(3));

static void Main(String[] args) {
	var zs = System.Console.ReadLine().Split(' ');
	double b = double.Parse(zs[0]); 
	double g = double.Parse(zs[1]);
	int bs = 3;
	int chs = 6;       
	double sum = 0;
	double pb = b / (g + b);
	double pg = 1.0 - pb;
	for(int i = bs;i<=chs;i++){
		sum += comb(chs, i) * Math.Pow(pb,i) * Math.Pow(pg, (chs-i));
	}
	System.Console.WriteLine(Math.Round(sum,3).ToString("f3"));
}

static double comb(double n, double r){
	var nf = f(n);
	var rf = f(r);
	var nrf = f(n-r);
	return nf / ( rf * (nrf));
}

static double f(double i)
{
	if (i < 2){
		i = 1;
	}
	double l = i;
	while(i-->1){
		l = l*i;
	}
	return l;
}

import math

boys, girls = map(float, input().split())
p_boys = boys/(boys + girls)
p_girls = 1 - p_boys
b = []
n_children = 6
n_boys = 3
for i in range(n_boys, n_children+1):
    answer = math.comb(6, i) * (p_boys ** i) * (p_girls ** (n_children - i))
    b.append(answer)
    
print(round(sum(b), 3))