'''
https://beta.atcoder.jp/contests/agc023/submissions/2426081
'''
n = int(input())
A = map(int, input().split())
B = {0:1}
s = 0
ans = 0
for a in A:
    s += a
    B_s = B.get(s, 0) 
    ans += B_s
    B[s] = B_s + 1
print(ans)