import sys
def I(): return int(sys.stdin.readline().rstrip())
def S(): return sys.stdin.readline().rstrip()


N = I()
p,q = float(S()),float(S())

if p == 1:
    print(1)
else:
    ans = 0
    for _ in range(N):
        ans = p+(q**2*ans)/(1-p*ans)
    print(ans)