#include<bits/stdc++.h>

using namespace std;
const int N=25;
int n,ans;
int a[N];
void dfs(int k,int sm,int sz){
    if(k==1+n){
        if(sm==sz&&sm>0){
            ans++;
        } 
        return; 
    }
    int hs=k;
    dfs(k+1,sm,sz);
    dfs(k+1,sm+a[hs],sz);
    dfs(k+1,sm,sz+a[hs]);
    return;
}
int main(){
    freopen("subsets.in","r",stdin);
    freopen("subsets.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    dfs(1,0,0);
    cout<<ans/2<<"\n";
    return 0;
}