#include<cstdio>#include<cstring>#include<cctype>#include<algorithm>using namespace std;#define rep(i,s,t) for(int i=s;i<=t;i++)#define dwn(i,s,t) for(int i=s;i>=t;i--)#define clr(x,c) memset(x,c,sizeof(x))int read(){    int x=0;char c=getchar();    while(!isdigit(c)) c=getchar();    while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();    return x;}const int nmax=25;int a[nmax];int main(){    int n=read(),sum=0;    rep(i,1,n) a[i]=read(),sum+=a[i];    if(sum%2) {        printf("0\n");return 0;    }    int cur=1,ans=0,tot=0;sum>>=1;    rep(i,1,n-1){        tot+=a[i];        while(tot>sum) tot-=a[cur++];        if(tot==sum) ans++;    }    printf("%d\n",ans*(ans-1)>>1);    return 0;}

N<= 20