You are given an integer sequence of length N. The i-th term in the sequence is a_i. In one operation, you can select a term and either increment or decrement it by one.  At least how many operations are necessary to satisfy the following conditions?    * For every i (1≤i≤n), the sum of the terms from the 1-st through i-th term is not zero.   * For every i (1≤i≤n-1), the sign of the sum of the terms from the 1-st through i-th term, is different from the sign of the sum of the terms from the 1-st through (i+1)-th term.
import numpy as np

n = int(input())
A = [int(x) for x in input().split()]
sum_start_plus = 0
sum_start_minus = 0
ans_start_plus = 0
ans_start_minus = 0


for i in range(n):
    sum_start_plus += A[i]
    if i % 2 == 0:
        if np.sign(sum_start_plus) == 1:
            continue
        else:
            ans_start_plus += abs(1 - sum_start_plus)
            sum_start_plus = 1
    else:
        if np.sign(sum_start_plus) == -1:
            continue
        else:
            ans_start_plus += abs(-1 - sum_start_plus)
            sum_start_plus = -1


for i in range(n):
    sum_start_minus += A[i]
    print(sum_start_minus)
    if i % 2 == 0:
        if np.sign(sum_start_minus) == -1:
            continue
        else:
            ans_start_minus += abs(-1 - sum_start_minus)
            sum_start_minus = -1
    else:
        if np.sign(sum_start_minus) == 1:
            continue
        else:
            ans_start_minus += abs(1 - sum_start_minus)
            sum_start_minus = 1

print(min(ans_start_plus, ans_start_minus))
n = int(input())
A = [int(x) for x in input().split()]
sum_start_plus = 0
sum_start_minus = 0
ans_start_plus = 0
ans_start_minus = 0
flag_start_plus = True
flag_start_minus = True


for a in A:
    sum_start_plus += a
    if flag_start_plus:
        flag_start_plus = False
        if sum_start_plus > 0:
            continue
        else:
            ans_start_plus += abs(1 - sum_start_plus)
            sum_start_plus = 1
    else:
        flag_start_plus = True
        if sum_start_plus < 0:
            continue
        else:
            ans_start_plus += abs(-1 - sum_start_plus)
            sum_start_plus = -1


for a in A:
    sum_start_minus += a
    if flag_start_minus:
        flag_start_minus = False
        if sum_start_minus < 0:
            continue
        else:
            ans_start_minus += abs(-1 - sum_start_minus)
            sum_start_minus = -1
    else:
        flag_start_minus = True
        if sum_start_minus > 0:
            continue
        else:
            ans_start_minus += abs(1 - sum_start_minus)
            sum_start_minus = 1

print(min(ans_start_plus, ans_start_minus))