n = int(input())
A = list(map(int,input().split()))

S = []
S.append(0)
for i in range(n):
    tmp = S[i]+A[i]
    S.append(tmp)
count = 0
# for k in range(1,n+1):
#     for i in range(n-k+1):
#         total = S[k+i]-S[i]
#         if (total == 0):
#             count += 1
C = set(S)
count = len(S)-len(C)
print(count)