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#include <iostream>
#include <cstdint>
#include <vector>

namespace {
	using std::ios_base, std::cin, std::cout;
	using std::vector;
	using uint_t = uint32_t;
	using int_t = int32_t;
	using vec_t = std::vector<int_t>;

	uint_t generate_buc(vec_t const & a, vec_t & buc) {
		uint_t n = a.size(), prev = 0, beg = 0, prev_beg;
		uint_t cnt_0 = 0, tmp;
		for (uint_t j = 0; j < n; ++j) {
			tmp = a[j] + prev;
			buc.push_back(tmp);
			if (tmp == 0) ++cnt_0;
			prev += a[j];
		}
		while (buc.size() - beg > 1) {
			prev_beg = beg;
			beg = buc.size();
			for (uint_t j = prev_beg + 1; j < beg; ++j) {
				tmp = buc[j] - buc[prev_beg];
				buc.push_back(tmp);
				if (tmp == 0) ++cnt_0;
			}
		}
		return cnt_0;
	}

	uint_t count_3_numbers_no_zero(vec_t const & buc) {
		uint_t cnt = 0, tmp;
		for (uint_t i = 0; i < buc.size() - 2; ++i)
			for (uint_t j = i + 1; j < buc.size() - 1; ++j) {
				if (buc[i] || buc[j]) {
					tmp = buc[i] + buc[j];
					for (uint_t k = j + 1; k < buc.size(); ++k) {
						if (tmp + buc[k] == 0)
							++cnt;
					}
				}
			}
		return cnt;
	}

	uint_t n_over_3(uint_t n) {
		if (n < 3) return 0;
		if (n == 3) return 1;
		if (n == 4) return 4;
		vector<uint_t> vec({6, 4});
		uint_t prev;
		for (uint_t i = 5; i <= n; ++i) {
			prev = i - 1;
			vec[0] += prev;
			prev = vec[0] - prev;
			vec[1] += prev;
		}
		return vec[1];
	}

	bool all_the_same_sign(vec_t const & buc) {
		bool same = true;
		bool positive = false, negative = false;
		uint_t k = 0;
		while (same && k < buc.size()) {
			if (buc[k] == 0)  {
				same = false;
			} else if (!positive && buc[k] > 0) {
				positive = true;
			} else if (!negative && buc[k] < 0) {
				negative = true;
			}
			if (positive && negative)
				same = false;
			++k;
		}
		return same;
	}
};

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	uint_t n;
	int_t ai;
	bool positive = false;
	bool negative = false;
	bool zero = false;
	vec_t a;
	cin >> n;
	for (uint_t k = 0; k < n; ++k) {
		cin >> ai;
		a.push_back(ai);
		if (!zero && ai == 0) zero = true;
		if (!positive && ai > 0) positive = true;
		if (!negative && ai < 0) negative = true;
	}

	vec_t buc;
	uint_t result;
	uint_t cnt_0 = generate_buc(a, buc);
	if (!zero && positive != negative) {
		result = 0;
	} else if (cnt_0 == buc.size()) {
		result = n_over_3(buc.size());
	} else if (all_the_same_sign(buc)) {
		result = 0;
	} else {
		result = n_over_3(cnt_0) + count_3_numbers_no_zero(buc);
	}
	cout << result << '\n';
}