#include <bits/stdc++.h>
using namespace std;
int n, a[40], arr[2][200001], tot[2];
int main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) cin >> a[i];
    sort(a, a + n);
    int len1 = n / 2, len2 = n - n / 2;
    long long cnt = 0;
    for (int i = 1; i < 1 << len1; i++) {
        int m = 0, x = 0;
        for (int j = 0; j < len1; j++)
            if (i & (1 << j)) {
                x += a[j];
                m++;
            }
        arr[m & 1][tot[m & 1]++] = x;
        if (x == 0 && (m & 1) == 0)
            cnt++;
    }
    for (int i = 0; i < 2; i++) sort(arr[i], arr[i] + tot[i]);
    for (int i = 1; i < 1 << len2; i++) {
        int m = 0, x = 0;
        for (int j = 0; j < len2; j++)
            if (i & (1 << j)) {
                x += a[j + len1];
                m++;
            }
        if (x == 0 && (m & 1) == 0)
            cnt++;
        cnt += upper_bound(arr[m & 1], arr[m & 1] + tot[m & 1], -x) -
               lower_bound(arr[m & 1], arr[m & 1] + tot[m & 1], -x);
    }
    cout << cnt;
    return 0;
}