#include<iostream.h>
#include<fstream.h>
ifstream f("nrtri.in");
ofstream g("nrtri.out");

int main()
{
     int n,i,v[100],a,b,c,nr=0,j,aux,x ;  
    f >> n;    
for (i=1; i<=n; i++)
    f >> v[i];
    

   for (i=1; i<=n-1; i++)
   for (j=i+1; j<=n; j++)
      if (v[i]>v[j])
      {
        aux=v[i];
       v[i]=v[j];
		v[j]=aux;
      }
   for (i=3; i<=n; i++)
   {
	   a=v[i];
	   b=v[i-1];
	   c=v[i-2];
	   if (a+b>c)
		   nr++;
   }
   
   g << nr;
}