#include <cstdio>
#include <cstdlib>
#define ll long long
#define maxn 300000
using namespace std;
ll a[40];
struct SplayTree {
    struct node {
        int lson, rson, father;
        ll val, cnt;
    } tree[maxn];
    int root, size;

private:
    void zig(int x) {
        int y = tree[x].father;
        tree[x].father = tree[y].father;
        if (tree[y].father)
            if (tree[tree[y].father].lson == y)
                tree[tree[y].father].lson = x;
            else
                tree[tree[y].father].rson = x;
        int z = tree[x].rson;
        tree[y].lson = z;
        if (z)
            tree[z].father = y;
        tree[y].father = x;
        tree[x].rson = y;
    }
    void zag(int x) {
        int y = tree[x].father;
        tree[x].father = tree[y].father;
        if (tree[y].father)
            if (tree[tree[y].father].lson == y)
                tree[tree[y].father].lson = x;
            else
                tree[tree[y].father].rson = x;
        int z = tree[x].lson;
        tree[y].rson = z;
        if (z)
            tree[z].father = y;
        tree[y].father = x;
        tree[x].lson = y;
    }
    void splay(int x) {
        while (tree[x].father) {
            int y = tree[x].father, z = tree[y].father;
            if (!z) {
                if (tree[y].lson == x)
                    zig(x);
                else
                    zag(x);
            } else {
                if (tree[z].lson == y && tree[y].lson == x) {
                    zig(y);
                    zig(x);
                } else if (tree[z].rson == y && tree[y].rson == x) {
                    zag(y);
                    zag(x);
                } else if (tree[z].lson == y && tree[y].rson == x) {
                    zag(x);
                    zig(x);
                } else {
                    zig(x);
                    zag(x);
                }
            }
        }
        root = x;
    }
    void insert(int pos, int x) {
        if (!root) {
            root = x;
            return;
        }
        if (tree[pos].val < tree[x].val) {
            if (tree[pos].rson)
                insert(tree[pos].rson, x);
            else {
                tree[pos].rson = x;
                tree[x].father = pos;
            }
        } else {
            if (tree[pos].lson)
                insert(tree[pos].lson, x);
            else {
                tree[pos].lson = x;
                tree[x].father = pos;
            }
        }
        return;
    }
    int build(ll x) {
        tree[++size].val = x;
        tree[size].cnt = 1;
        return size;
    }
    ll query(int pos, ll x) {
        if (!pos)
            return 0;
        if (tree[pos].val == x)
            return tree[pos].cnt;
        if (tree[pos].val < x)
            return query(tree[pos].rson, x);
        else
            return query(tree[pos].lson, x);
    }
    int find(int pos, ll x) {
        if (!pos)
            return 0;
        if (tree[pos].val == x)
            return pos;
        if (tree[pos].val < x)
            return find(tree[pos].rson, x);
        else
            return find(tree[pos].lson, x);
    }

public:
    void push(ll x) {
        int f = find(root, x);
        if (f)
            tree[f].cnt++;
        else
            insert(root, build(x));
    }
    ll count(ll x) { return query(root, x); }
    void clear() { size = root = 0; }
} s;
int main() {
    int n, t;
    ll ans = 0;
    scanf("%d", &n);
    for (register int i = 1; i <= n; ++i) {
        scanf("%lld", &a[i]);
    }
    s.clear();
    s.push(0);
    t = 1 << (n >> 1);
    for (register int i = 1; i < t; ++i) {
        ll sum = 0;
        for (register int j = 1; j <= n >> 1; ++j) {
            if ((1 << j - 1) & i)
                sum += a[j];
        }
        s.push(sum);
    }
    t = 1 << ((n + 1) >> 1);
    for (register int i = 0; i < t; ++i) {
        ll sum = 0;
        for (register int j = 1; j <= (n + 1) >> 1; ++j) {
            if ((1 << j - 1) & i)
                sum += a[n / 2 + j];
        }
        ans += s.count(-sum);
    }
    ans--;
    printf("%lld", ans);
    return 0;
}