from collections import defaultdict

N=int(input())
A=list(map(int,input().split()))
C=[0]+A
for i in range(1,N+1):
    C[i]+=C[i-1]
dct=defaultdict(list)
for i in range(N):
    dct[(A[i],C[i]-i*A[i])].append(i)
ans=N*(N-1)//2
for lst in dct.values():
    le=len(lst)
    ans-=le*(le-1)//2
ans+=1
print(ans)