output_description: Find the number of the non-empty contiguous subsequences of A whose sum is 0.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 A_2 ... A_N
attempt: import sys
  import math
  import copy
  import heapq
  from functools import cmp_to_key
  from bisect import bisect_left, bisect_right
  from collections import defaultdict, deque, Counter
  
  sys.setrecursionlimit(1000000)
  
  # input aliases
  input = sys.stdin.readline
  getS = lambda: input().strip()
  getN = lambda: int(input())
  getList = lambda: list(map(int, input().split()))
  getZList = lambda: [int(x) - 1 for x in input().split()]
  
  INF = float("inf")
  MOD = 10**9 + 7
  divide = lambda x: pow(x, MOD - 2, MOD)
  
  
  def nck(n, k, kaijyo):
      return (npk(n, k, kaijyo) * divide(kaijyo[k])) % MOD
  
  
  def npk(n, k, kaijyo):
      if k == 0 or k == n:
          return n % MOD
      return (kaijyo[n] * divide(kaijyo[n - k])) % MOD
  
  
  def fact_and_inv(SIZE):
      inv = [0] * SIZE  # inv[j] = j^{-1} mod MOD
      fac = [0] * SIZE  # fac[j] = j! mod MOD
      finv = [0] * SIZE  # finv[j] = (j!)^{-1} mod MOD
      inv[1] = 1
      fac[0] = fac[1] = 1
      finv[0] = finv[1] = 1
      for i in range(2, SIZE):
          inv[i] = MOD - (MOD // i) * inv[MOD % i] % MOD
          fac[i] = fac[i - 1] * i % MOD
          finv[i] = finv[i - 1] * inv[i] % MOD
  
      return fac, finv
  
  
  def renritsu(A, Y):
      # example 2x + y = 3, x + 3y = 4
      # A = [[2,1], [1,3]])
      # Y = [[3],[4]] または [3,4]
      A = np.matrix(A)
      Y = np.matrix(Y)
      Y = np.reshape(Y, (-1, 1))
      X = np.linalg.solve(A, Y)
  
      # [1.0, 1.0]
      return X.flatten().tolist()[0]
  
  
  class TwoDimGrid:
      # 2次元座標 -> 1次元
      def __init__(self, h, w, wall="#"):
          self.h = h
          self.w = w
          self.size = (h + 2) * (w + 2)
          self.wall = wall
          self.get_grid()
          # self.init_cost()
  
      def get_grid(self):
          grid = [self.wall * (self.w + 2)]
          for i in range(self.h):
              grid.append(self.wall + getS() + self.wall)
  
          grid.append(self.wall * (self.w + 2))
          self.grid = grid
  
      def init_cost(self):
          self.cost = [INF] * self.size
  
      def pos(self, x, y):
          # 壁も含めて0-indexed 元々の座標だけ考えると1-indexed
          return y * (self.w + 2) + x
  
      def getgrid(self, x, y):
          return self.grid[y][x]
  
      def get(self, x, y):
          return self.cost[self.pos(x, y)]
  
      def set(self, x, y, v):
          self.cost[self.pos(x, y)] = v
          return
  
      def show(self):
          for i in range(self.h + 2):
              print(self.cost[(self.w + 2) * i : (self.w + 2) * (i + 1)])
  
      def showsome(self, tgt):
          for t in tgt:
              print(t)
          return
  
      def showsomejoin(self, tgt):
          for t in tgt:
              print("".join(t))
          return
  
      def search(self):
          grid = self.grid
          move = [(0, 1), (0, -1), (1, 0), (-1, 0)]
          move_eight = [
              (0, 1),
              (0, -1),
              (1, 0),
              (-1, 0),
              (1, 1),
              (1, -1),
              (-1, 1),
              (-1, -1),
          ]
          # for i in range(1, self.h+1):
          #     for j in range(1, self.w+1):
          #         cx, cy = j, i
          #         for dx, dy in move_eight:
          #             nx, ny = dx + cx, dy + cy
  
  
  def solve():
      n = getN()
      nums = [0] + getList()
      for i in range(n):
          nums[i + 1] += nums[i]
      cnt = Counter(nums)
      fac, _ = fact_and_inv(n + 2)
      # print(cnt, nums)
      ans = 0
      for v in cnt.values():
          if v != 1:
              ans += nck(v, 2, fac)
  
      print(ans)
  
  
  def main():
      n = getN()
      for _ in range(n):
          solve()
  
      return
  
  
  if __name__ == "__main__":
      # main()
      solve()
  
problem_description: Statement
  
  We have an integer sequence A, whose length is N.
  
  Find the number of the non-empty **contiguous** subsequences of A whose sums
  are 0. Note that we are counting **the ways to take out subsequences**. That
  is, even if the contents of some two subsequences are the same, they are
  counted individually if they are taken from different positions.
samples: [{"input": "6\n    1 3 -4 2 2 -2", "output": "3\n    \n\nThere are three contiguous subsequences whose sums are 0: (1,3,-4), (-4,2,2)\nand (2,-2).\n\n* * *"}, {"input": "7\n    1 -1 1 -1 1 -1 1", "output": "12\n    \n\nIn this case, some subsequences that have the same contents but are taken from\ndifferent positions are counted individually. For example, three occurrences\nof (1, -1) are counted.\n\n* * *"}, {"input": "5\n    1 -2 3 -4 5", "output": "0\n    \n\nThere are no contiguous subsequences whose sums are 0."}]