#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <vector>

using namespace std;

#define file_in "numarare.in"
#define file_out "numarare.out"

#define nmax 101001

int n;
int s[nmax];

void citire()
{
    int i;
    freopen(file_in,"r",stdin);
    freopen(file_out,"w",stdout);

    scanf("%d", &n);
    for (i=1;i<=n;++i)
          scanf("%d", &s[i]);

}

void solve()
{
    int i,j,k,nr;
    nr=0;

    for (i=1;i<=n;++i)
         for (j=i+1;j<=n;++j)
         {
             int ok=0;
             for (k=1;k<=j/2 && !ok;++k)
                  if (s[i]+s[j]!=s[i+k-1]+s[j-k+1]) ok=1;
              if (!ok && (j-i+1)%2==0) nr++;
         }
    printf("%d\n", nr);
}

int main()
{
    citire();
    solve();

    fclose(stdin);
    fclose(stdout);

    return 0;
}