# 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) 
ans = 0
c = 39916800
for i in range(N + 1):
    assert(c * (B ** (i + 1) - A ** (i + 1)) % (i + 1) == 0)
    ans += (c * K[i] * (B ** (i + 1) - A ** (i + 1))) // (i + 1) 

print(ans // c)