# coding : utf-8

import numpy as np

N = int(input())

A = [int(i) for i in input().split()]


count = 0

#dist = [0 for i in range(N)]
dist = np.zeros(N)
suml = sum(A)

for i in range(N):
	dist[:i+1] += A[i]
	#print(dist)
	count += sum(dist[:i+1]==0)

#print(dist)

print(count)