#include <iostream>
#include <fstream>
using namespace std;
int verificare(int a,int b,int c)
{
    if(a+b>=c and a+c>=b and b+c>=a)
        return 1;
    else
        return 0;
}
int main()
{
    int i,j,q,k=0,v[800],n;
    ifstream f("nrtri.in");
    ofstream g("nrtri.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++)
        {
            q=j+1;
            while(q<=n)
            {
                if(verificare(v[i],v[j],v[q])==1)
                    k++;
                q++;
            }
        }
    }
    g<<k;
    return 0;
}