#include <bits/stdc++.h>
#include <map>

using namespace std;
typedef long long ll;
int main() {
    cin.sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    int nums[n];
    for (int i = 0; i < n; i++) {
        cin >> nums[i];
    }
    map<int, ll> jmp;
    map<int, ll> omp;
    int mid = n / 2, els = n - mid;
    for (ll mask = 0, toll = 1 << mid; mask < toll; mask++) {
        int count = 0;
        ll sum = 0;
        for (int i = 0; i < mid; i++) {
            if ((mask >> i) & 1) {
                count++;
                sum += nums[i];
            }
        }
        if (count % 2 == 0) {
            omp[sum]++;
        } else {
            jmp[sum]++;
        }
    }
    ll ans = -1;
    for (ll mask = 0, toll = 1 << els; mask < toll; mask++) {
        int count = 0;
        ll sum = 0;
        for (int i = 0; i < els; i++) {
            if ((mask >> i) & 1) {
                count++;
                sum += nums[i + mid];
            }
        }
        if (count % 2 == 0) {
            ans += omp[-sum];
        } else {
            ans += jmp[-sum];
        }
    }
    cout << ans;
    return 0;
}