#!/usr/bin/ python3.8
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

N, p, q = read().split()
N = int(N)
p, q = map(float, (p, q))

if q == 0:
    print(0)
    exit()
elif p == 0:
    print(1)
    exit()
elif p + q == 1:
    print(0)
    exit()

A = np.zeros((N + N + 2, N + N + 2), np.float64)
np.fill_diagonal(A, 1.0)
np.fill_diagonal(A[1:N, 2: N + 1], -q)
np.fill_diagonal(A[N + 2:N + N + 1, N + 1:N + N], -q)
np.fill_diagonal(A[1:N, N + 1: N + N], -p)
np.fill_diagonal(A[N + 2:N + N + 1, 2: N + 1], -p)

y = np.zeros(N + N + 2)
y[N + 1] = 1

x = np.linalg.solve(A, y)
print(x[1])