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#include <bits/stdc++.h>
#ifdef LOC
#include "debuglib.h"
#else
#define deb(...)
#define DBP(...)
#endif
using namespace std;
using   ll         = long long;
using   vi         = vector<int>;
using   pii        = pair<int, int>;
#define pb           push_back
#define mp           make_pair
#define x            first
#define y            second
#define rep(i, b, e) for (int i = (b); i < (e); i++)
#define each(a, x)   for (auto& a : (x))
#define all(x)       (x).begin(), (x).end()
#define sz(x)        int((x).size())

constexpr int MAX_N = 500;
constexpr int MAX_V = 20'000;
constexpr int SUM = MAX_N * MAX_V * 3 + 5;

int bufTriples[SUM*2], bufPairs[SUM*2];
int *triples = bufTriples+SUM, *pairs = bufPairs+SUM;

void run() {
	int n; cin >> n;
	vi pref(n+1);

	rep(i, 0, n) {
		cin >> pref[i+1];
		pref[i+1] += pref[i];
	}

	ll ans = 0;

	for (int k = n-1; k >= 0; k--) {
		rep(i, 0, n+1) rep(j, i+1, n+1) {
			int a = pref[k+1], b = pref[i], c = pref[j];
			triples[a-b+c]++;
		}
		rep(i, 0, n+1) rep(j, i+1, n+1) {
			int a = pref[k], b = pref[i], c = pref[j];
			ans += triples[a+b-c];
		}
	}

	rep(i, 0, n+1) rep(j, i+1, n+1) {
		int a = pref[i], b = pref[j];
		pairs[b-a]++;
	}

	rep(i, 0, n+1) rep(j, i+1, n+1) {
		int a = pref[i], b = pref[j];
		ans -= pairs[(a-b)*2] * 3;
		ans += (a == b) * 2;
	}

	ans /= 6;
	cout << ans << '\n';
}

int main() {
	cin.sync_with_stdio(0); cin.tie(0);
	cout << fixed << setprecision(10);
	run();
	cout << flush; _Exit(0);
}