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

int n, m;
LL ans, a[36];
map<long long, int> mp0;
map<long long, int> mp1;
int main() {
    // freopen("10.in","r",stdin);
    // freopen("10.out","w",stdout);
    scanf("%d", &n);
    m = (n >> 1);
    for (int i = 0; i < n; i++) {
        scanf("%lld", &a[i]);
    }
    int maxn = (1 << m);
    for (int p = 1; p < maxn; p++) {
        LL sum = 0;
        int cnt = 0;
        for (int i = 0; i < m; i++) {
            if ((p >> i) & 1) {
                cnt++;
                sum += a[i];
            }
        }
        if (cnt % 2 != 0) {
            mp1[sum]++;
        } else {
            mp0[sum]++;
            if (sum == 0)
                ans++;
        }
    }
    maxn = (1 << (n - m));
    for (int p = 1; p < maxn; p++) {
        LL sum = 0;
        int cnt = 0;
        for (int i = 0; i < n - m; i++) {
            if ((p >> i) & 1) {
                cnt++;
                sum += a[i + m];
            }
        }
        if (cnt % 2 != 0) {
            ans = ans + mp1[-sum];
        } else {
            ans = ans + mp0[-sum];
            if (sum == 0)
                ans++;
        }
    }
    printf("%lld\n", ans);
}