#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
LL x,sum[100005];int n;LL cnt=0,cnt2=0;
int main(){
    scanf("%d",&n);
    for (int i=1;i<=n;++i){scanf("%lld",&x);sum[i]+=sum[i-1]+x;}
    if (sum[n]%3){return putchar('0'),0;}
    LL ans=sum[n]/3;
    for (int i=1;i<=n;++i){
        if (sum[i]==ans){++cnt;}
        if (sum[i]==(ans*2)){++cnt2;}
    }
    printf("%lld",cnt*cnt2);
    return 0;
}