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#include <bits/stdc++.h>
using namespace std;

#define fwd(i, a, n) for (int i = (a); i < (n); i ++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) begin(X), end(X)
#define sz(X) ((int)X.size())
#define st first
#define nd second
#define pii pair<int, int>
#define vi vector<int>
#define ll long long

#ifdef LOC
auto &operator << (auto &out, pair<auto, auto> a) {
	return out << "(" << a.st << ", " << a.nd << ")";
}

auto &operator << (auto &out, auto a) {
	out << "{";
	for (auto b : a)
		out << b << ", ";
	return out << "}";
}

void dump(auto... x) { ((cerr << x << ", "), ...) << '\n'; }

#define debug(x...) cerr << "[" #x "]: ", dump(x)
#else
#define debug(...) 0
#endif

const int maxN = 500 + 10;

int n;
int a[maxN];
int b[maxN * maxN];
int N = 0;

const int magic = 31 * 1000 * 1000;
int tab[2 * magic];

void prep() {
	rep(i, n) {
		int suma = 0;
		fwd(j, i, n) {
			suma += a[j];
			b[N ++] = suma;
		}
	}
	sort(b, b + N);
}

ll count_one() {
	ll ans = 0;
	rep(i, N)
		if (b[i] == 0)
			ans += 1;
	return ans;
}

ll count_two() {
	rep(i, N)
		tab[magic + b[i]] += 1;
	ll ans = 0;
	rep(i, N)
		ans += tab[magic - 2 * b[i]];
	rep(i, N)
		tab[magic + b[i]] -= 1;
	return ans;
}

ll count_three() {
	ll ans = 0;
	int pref = 0;
	rep(i, n) {
		rep(j, N)
			tab[magic + b[j] - pref] += 1;
		pref += a[i];
		rep(j, N)
			ans += tab[magic - b[j] - pref];
	}
	return ans;
}

int32_t main() {
   	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n;
	rep(i, n)
		cin >> a[i];
	prep();
	ll c1 = count_one();
	ll c2 = count_two() - c1;
	ll c3 = count_three();
	c3 -= c1 + 3 * c2;
	assert(c3 % 6 == 0);
	c3 /= 6;
	cout << c3 << '\n';
   	return 0;
}