//Numarare triunghiuri
#include <fstream>
using namespace std;
  int nr,n,v[100],i,a,j,l;
  int main()
{
    ifstream f("nrtriunghiuri.in");
    ofstream g("nrtriunghiuri.out");
     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])
{
     a=v[i];
     v[i]=v[j];
     v[j]=a;
}
   for(i=1;i<=n;i++)
   for(j=i+1;j<=n;j++)
   for(l=j+1;l<=n;l++)
    if(v[i]+v[j]>=v[l])   
     nr++;
     g<<nr;
return 0;
}