from functools import reduce
from fractions import gcd
import math
import bisect
import itertools
import sys
input = sys.stdin.readline
INF = float("inf")


# 処理内容
def main():
    P, Q = map(float, input().split())
    P /= 100
    Q /= 100
    a = P*Q + (1-P)*(1-Q)
    b = P*Q
    R = b / a * 100
    print(R)

if __name__ == '__main__':
    main()