import sys
from collections import deque
sys.setrecursionlimit(20000000)
input = sys.stdin.readline
n = int(input())
p = float(input())
q = float(input())
dp = [[0,0]for i in range(n+2)]
dp[1][0] = 1
if p + q == 1:
    print(1-q**n)
    exit()
for i in range(6*n*2):
    dp2 = [[0,0]for i in range(n+2)]
    for j in range(n,0,-1):
        dp2[j+1][0] += dp[j][0]*q
        dp2[j-1][1] += dp[j][1]*q
        dp2[j-1][1] += dp[j][0]*p
        dp2[j+1][0] += dp[j][1]*p
    dp2[0][0] += dp[0][0]
    dp2[0][1] += dp[0][1]
    dp = dp2
print(sum(dp[0]))