#include <iostream>
#include <fstream>
using namespace std;

ifstream fin("nrtri.in");
ofstream fout("nrtri.out");

bool EsteTriunghi(int a, int b, int c);

int main()
{
    int a[800], n, cnt = 0;
    fin >> n;

    for (int i = 0; i < n; ++i)
        fin >> a[i];

    for (int i = 0; i < n; ++i)
        for (int j = i + 1; j < n; ++j)
            for (int k = j + 1; k < n; ++k)
                if (EsteTriunghi(a[i], a[j], a[k]))
                    cnt++;

    fout << cnt;
    return 0;
}

bool EsteTriunghi(int a, int b, int c)
{
    if (a + b >= c && a + c >= b && b + c >= a)
        return true;
    return false;
}