#include <stdio.h>
#include <string.h>
#include <map>
#define llu long long
using namespace std;
int n;
int a[36] = { 0 }, *p = a, ans = 0;
map<llu, int> mp1;
map<llu, int> mp2;
int main() {
    int i, ban, nn;
    scanf("%d", &n);
    ban = n >> 1;
    nn = n - ban;
    for (i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    for (int mask = 0, tot = 1 << ban; mask < tot; mask++) {
        llu sum = 0, t = 0;
        for (int i = 0; i < ban; i++) {
            if ((mask >> i) & 1) {
                sum += a[i];
                t++;
            }
        }

        if (t & 1) {
            if (mp1.find(sum) != mp1.end())
                mp1[sum]++;
            else if (mp1.find(sum) == mp1.end())
                mp1[sum] = 1;
        } else if (!(t & 1) && t != 0) {
            if (sum == 0 && t != 0) {
                ans++;
            }
            if (mp2.find(sum) != mp2.end())
                mp2[sum]++;
            else if (mp2.find(sum) == mp2.end())
                mp2[sum] = 1;
        }
    }

    for (int mask = 0, tot = 1 << nn; mask < tot; mask++) {
        llu sum = 0, t = 0;
        for (int i = ban; i < n; i++) {
            if ((mask >> (i - ban)) & 1) {
                sum += -a[i];
                t++;
            }
        }
        if (t & 1) {
            if (mp1.find(sum) != mp1.end())
                ans += mp1[sum];
        } else if (!(t & 1) && t != 0) {
            if (sum == 0 && t != 0) {
                ans++;
            }
            if (mp2.find(sum) != mp2.end())
                ans += mp2[sum];
        }
    }
    printf("%d", ans);
    return 0;
}