1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4
 5 int n,mid,ans,a[30],num,tmp[1<<11];
 6 int tot=1,pre[60010],son[60010],now[1<<11];
 7 bool b[1<<21];
 8
 9 int cnt;
10 struct Node{int sum,set;}f[60010];
11
12 bool cmp(Node a,Node b){return a.sum<b.sum;}
13
14 void DFS1(int dep,int sum,int set){
15     if(dep==mid+1){
16         tot++;pre[tot]=now[set];
17         now[set]=tot;son[tot]=sum;
18     }
19     else{
20         DFS1(dep+1,sum,set);
21         DFS1(dep+1,sum+a[dep],set|(1<<(dep-1)));
22         DFS1(dep+1,sum-a[dep],set|(1<<(dep-1)));
23     }
24 }
25
26 void DFS2(int dep,int sum,int set){
27     if(dep==n+1){
28         ++cnt;
29         f[cnt].sum=sum;f[cnt].set=set;
30     }
31     else{
32         DFS2(dep+1,sum,set);
33         DFS2(dep+1,sum+a[dep],set|(1<<(dep-1)));
34         DFS2(dep+1,sum-a[dep],set|(1<<(dep-1)));
35     }
36 }
37
38 int main(){
39     scanf("%d",&n);mid=n/2;
40     for(int i=1;i<=n;i++)scanf("%d",&a[i]);
41     DFS1(1,0,0);DFS2(mid+1,0,0);
42     sort(f+1,f+cnt+1,cmp);
43     for(int i=0;i<=(1<<mid)-1;i++){
44         num=0;
45         for(int p=now[i];p;p=pre[p])
46             tmp[++num]=son[p];
47         sort(tmp+1,tmp+num+1);
48         for(int j=1,k=1;j<=cnt;j++){
49             while(k<=num&&tmp[k]<f[j].sum)
50                 k++;
51             if(k==num+1)break;
52             if(tmp[k]==f[j].sum)
53                 b[i|f[j].set]=1;
54         }
55     }
56     for(int i=1;i<=(1<<n)-1;i++)
57         if(b[i])ans++;
58     printf("%d\n",ans);
59     return 0;
60 }