import numpy
from scipy.special import comb
import collections

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

cumulative_sum = numpy.cumsum(a)
cumulative_sum = numpy.append(cumulative_sum, 0)
count = collections.Counter(cumulative_sum)

ret = 0
for v in count.values():
    ret += int(comb(v, 2))
print(ret)


