N = int(input())
B = list(map(lambda x: int(x) - 1, input().split()))

tmp = 0
res = 0

for i in range(N):
    if B[i] == 0:
        res += abs(tmp)
    elif B[i] == -1:
        tmp -= 1
        res += abs(tmp)
    else:
        tmp += B[i]
        res += abs(tmp)

print(res)