#include <fstream>
#include <algorithm>

const int MaxN{ 800 };
int sir[MaxN];

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

int main()
{
    int n;

    std::ifstream fin{ "nrtri.in" };
    fin >> n;

    for (int i = 0; i != n; ++i)
        fin >> sir[i];

    int contor{ 0 };

    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(sir[i], sir[j], sir[k]))
                    ++contor;
            }
        }
    }

    std::ofstream fout{ "nrtri.out" };
    fout << contor;

    return 0;
}

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