public class Euler855 {
    public static String solve() {
        int a = 5, b = 8, DIGITS = 10;
        double log10val = a * lgammaLog10(b + 1) + b * lgammaLog10(a + 1) - 2 * lgammaLog10(a * b + 1);
        int exponent = (int) Math.floor(log10val);
        double mantissa = Math.pow(10.0, log10val - exponent);
        long scale = 1;
        for (int i = 0; i < DIGITS; i++)
            scale *= 10;
        long scaled = Math.round(mantissa * scale);
        if (scaled >= 10 * scale) {
            scaled /= 10;
            exponent++;
        }
        long intPart = scaled / scale, fracPart = scaled % scale;
        return intPart + "." + String.format("%0" + DIGITS + "d", fracPart) + "e" + exponent;
    }

    static double lgammaLog10(int n) {
        double sum = 0;
        for (int i = 1; i < n; i++)
            sum += Math.log10(i);
        return sum;
    }

    public static void main(String[] args) {
        System.out.println(solve());
    }
}