#include <bits/stdc++.h>
using namespace std;
int a[40];
typedef pair<long long, int> pp;
map<pp, int> mp;
int n;
long long num = 0;
void dfs1(long long sum, int len, int deep, int b[]) {
    if (deep == n / 2) {
        if (len != 0) {
            len = len % 2 + 2;
        }
        pp p(sum, len);
        mp[p]++;
        return;
    }
    dfs1(sum, len, deep + 1, b);
    dfs1(sum + b[deep], len + 1, deep + 1, b);
}
void dfs2(long long sum, int len, int deep, int c[]) {
    if (deep == n - n / 2) {
        if (len != 0) {
            len = len % 2 + 2;
        }
        if (len == 0) {
            pp t(0, 2);
            num = num + mp[t];
            return;
        } else {
            pp p(-sum, len);
            pp u(-sum, len - 2);
            num += mp[p] + mp[u];
            return;
        }
    }
    dfs2(sum, len, deep + 1, c);
    dfs2(sum + c[deep], len + 1, deep + 1, c);
}
int main() {
    int i, j;
    scanf("%d", &n);
    int b[n / 2];
    int c[n - n / 2];
    for (i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    sort(a, a + n);
    for (i = 0; i < n / 2; i++) {
        b[i] = a[i];
    }
    for (i = n / 2; i < n; i++) {
        c[i - n / 2] = a[i];
    }
    dfs1(0, 0, 0, b);
    dfs2(0, 0, 0, c);
    printf("%lld", num);
}