#include<stdio.h>
void sort(int a[1000],int &n)
{
     int i,k,y;
     for(i=1;i<n;i++)
{    for(k=i+1;k<=n;k++)
     if(a[i]>a[k])
     {
               
     y=a[i];
     a[i]=a[k];
     a[k]=y;
     }
     }}
int main ()
{
    freopen("nrtri.in","r",stdin);
    freopen("nrtri.out","w",stdout);
    int n,i,k,nrt=0,y;
    scanf("%d",&n);
    int x,j;
    int a[n];
    for(i=1;i<=n;i++)
    scanf("%d",&a[i]); 
   sort(a,n);
  //  for(i=1;i<=n;i++)
   // printf("%d ",a[i]);
    for(i=1;i<=n;i++)
    for(k=i+1;k<=n;k++)
    {
                       x=a[i];
                       y=a[k];
                       for(j=k+1;j<=n;j++)
                       if(x+y>=a[j] && a[j]+x>=y && a[j]+y>=x)
                                  nrt++;
                               
                                 }
                                  printf("%d ",nrt);
    return 0;
}