INF = 10 ** 9
MOD = 10 **9 + 7
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)

def main():
    p,q = map(float,input().split())
    print(100*p*q/(pow(10,4) - (p + q)*pow(10,2) + 2*p*q))
if __name__=='__main__':
    main()