#!/usr/bin/ python3.8
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

p0, q = map(int, read().split())
p0 /= 100
q /= 100


def solve(depth, p):
    if depth > 20:
        return 0.5
    if p < 0:
        p = 0
        return (1 / 3) + solve(depth + 1, p + q) / 3
    if p > 1:
        p = 1
        return (1 / 2) + solve(depth + 1, p - q) / 2
    x = (1 / 3) + solve(depth + 1, p + q) / 3
    y = (1 / 2) + solve(depth + 1, p - q) / 2
    return x * (1 - p) + y * p


x = solve(0, p0)
answer = 1 / 3 + x / 3
print(answer)