#include<stdio.h>
#define ll long long

 ll a[100001],s,st,dr,t=1,i,nr,n;
 
  int main()
{
	freopen("numarare.in","r",stdin);
	freopen("numarare.out","w",stdout);
	
  scanf("%lld\n",&n);
  for(i=1;i<=n;i++)
	  scanf("%lld",&a[i]);
  
  for(i=1;i<n;i++)
  {
	  st=i;
	  dr=i+1;
	  s=a[st]+a[dr];
      t=1;
	  nr++;
	while(t)
	{
    	if(st-1>=1) st--;
		else
			t=0;
		if(dr+1<=n) dr++;
		else
			t=0;
	if(t&&s==a[st]+a[dr])
         nr++;
	else
	    t=0;
	}
  }

printf("%lld\n",nr);
return 0;
  }