import sys
input = lambda : sys.stdin.readline().rstrip()

sys.setrecursionlimit(2*10**5+10)
write = lambda x: sys.stdout.write(x+"\n")
debug = lambda x: sys.stderr.write(x+"\n")
writef = lambda x: print("{:.12f}".format(x))

import numpy as np
n = int(input())
p = float(input())
q = float(input())
if q==0:
    x = 1
else:
    dp0 = [0]*n
    dp1 = [0]*n
    dp0[0] = np.array((1,0), dtype=np.float64)
    dp1[0] = np.array((0,1), dtype=np.float64)
    for i in range(1,n):
        dp0[i] = (dp0[i-1]- p*dp1[i-1]) / q
        dp1[i] = q*dp1[i-1] + p*dp0[i]
        v = np.linalg.norm(dp0[i])
        dp0[i], dp1[i] = dp0[i]/v, dp1[i]/v
    a0,b0 = dp0[n-1]
    a1,b1 = dp1[n-1]
    x = (b1-b0) / (a0-a1)
print(x)