# そのまま
import math
N, A, B = map(int, input().split())
K = [int(input()) for _ in range(N + 1)]
ans = 0
for i in range(N + 1):
    ans += K[i] * (B ** (i + 1) - A ** (i + 1)) / (i + 1) 
print(math.floor(ans))