p,q = map(lambda x: int(x)/100,input().split())
ans = 1/3
st = [(1/3,p)] #prob, p, used?
while st:
    prob, p = st.pop()
    if prob < 1e-12: continue
    ans += prob*((1.0-p)/3 + p/2)
    st.append((prob*((1.0-p)/3),min(1.0,p+q)))
    st.append((prob*p/2,max(0.0,p-q)))
print(ans)