/*#include <fstream>
#include <algorithm>
#include <string>
using namespace std;
int n,d, i, j,p[36000], c, l, a, b, m ,maxi, nr, v[1000];
ifstream fin("rachete.in");
ofstream fout("rachete.out");
string s;
int main()
{
    fin >> n >> m ;
      for ( i = 2; i <= 35000 ; ++i)
      {
         if (!p[i])
         {
             for (j = i + i; j <= n; j += i)
                    p[j] = 1;
         }
      }
      for (a = 1; a <= n * m ; ++a)
       {
           fin >> v[a];

           if  (p [a] == 0)
                v[a] = 0;
              else if (a - v[a] > maxi)
                        {
                            maxi = a - v[a];
                            ++nr;
                        }
                    else v[a] = 0;

       }
       fout << maxi << " " << nr + 1;
       for (b = 1; b <= n * m; ++b)
           {
               if (!(v[b]))
                    fout << v[b];
           }
    return 0;
}


#include <fstream>
#include <algorithm>
#include <string>
using namespace std;
int n,d, i, j,p[36000],k[36000], c, l, a, b, m[100][100] ,maxi, nr, v[1000];
ifstream fin("rachete.in");
ofstream fout("rachete.out");
string s;
int main()
{
      for ( i = 2; a <= 35000 ; ++i)
            {
                if (!p[i])
                {
                    for (j = i + i; j <= n; j += i)
                        p[j] = 1;
                }
                if (p[i] == 0)
                    k[i] = p[i];
            }

        for (i = 1; i <= n; ++i)
        for (j = 1; j <= n; ++j)
          {
              fin >> m[i][j];

            if (p[m[i][j]] == 0)
               m[i][j] = 0;
            else if (k[i] - m[i][j] > maxi)
                   {
                    maxi = k[i] - m[i][j];
                    ++nr;
                   }
          }
          fout << maxi << " " << nr + 1;
        for (i = 1; i <= n; ++i)
            {
                if (m[i][j] + maxi == k[i])
                fout << m[i][j];
            }


return 0;
}

#include <iostream>
#include <fstream>
#include <algorithm>
#include <string>
using namespace std;
int n, i, k, h, p, d, a, maxi, nr, r, v[1100], e[1100], g[1100];
ifstream fin("scara.in");
ofstream fout("scara.out");
string s;
int main()
{
    fin >> k >> h;

        for (i = 1; i <= h; ++i)
            {
            fin >> v[i];
            if (v[i] > maxi)
            maxi = v[i];
            }
        while (nr < k)
        {
            for (i = 2; i <= 1000; ++i)
            {
                for (d = 2; d * d <= i; d++)
                {
                    if (i % d != 0 && v[i] != a)
                    g[i] = i;
                    ++nr;
                }
            }
        }
        for (i = 1; i <= nr; ++i)
            fout << g[i];


    return 0;
}


#include <iostream>
#include <fstream>
#include <algorithm>
#include <string>
#include <cmath>
using namespace std;
int n, a, nr, j, i, b, m, g[1000], v[1000], maxi, mini;
ifstream fin("matrixdel.in");
ofstream fout("matrixdel.out");
string s;
int main()
{
    fin >> n >> m;
    maxi = 0;
    mini = 50000;
    for ( i = 1; i <= n; ++i)
        fin >> v[i];
    for ( i = n; i <= n + m; ++i)
        fin >> g[i];
    if (n > m)
        for ( i = 1; i <= n + m; ++i)
            {
            if (v[i] == g[i] && v[i] > maxi)
                maxi = v[i];
            if (v[i] == g[i] && v[i] < mini)
                mini = v[i];
            }
    else for ( i = 1; i <= m + n; ++i)
            {
            if (v[i] == g[i] && v[i] > maxi)
                maxi = v[i];
            if (v[i] == g[i] && v[i] < mini)
                mini = v[i];
            }
    for (i = 1; i <= n; ++i)
        {
        if (v[i] < mini)
            a += v[i];
        if (v[i] > maxi)
            a += v[i];
        }
    for (i = 1; i <= m; ++ i)
         {
        if (g[i] < mini)
            b += g[i];
        if (g[i] > maxi)
            b += g[i];
        }
    fout << mini << " " << maxi << " ";
    if (a > b)
        fout << 1;
        else if (a == b)
            fout << 0;
            else fout << 2;

    return 0;
}



#include <iostream>
#include <fstream>
#include <algorithm>
#include <string>
#include <cmath>
using namespace std;
int n, cod, a, b, c, d, nr, i;
ifstream fin("matrixdel.in");
ofstream fout("matrixdel.out");
string s;
int main()
{
    fin >> n;
    for (i = 1; i <= n; ++i)
    {
        nr = 0;
        fin >> cod;
        a = cod;
        b = 10;
        d = cod % 10;
        while ( cod != 0)
            {
                c = cod % 10;
                cod /= 10;
                ++nr;
            }
        while (b <= a)
            b *= 10;
        if (nr % 2 == 1)
            {
            if ( c < d )
                fout << (a - d)/ (b/10) + c << " ";
            else fout << a << " ";

            }
        else fout << a << " ";
    }

    return 0;
}
*/

/*

#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
using namespace std;
int i, n, maxi,nr, s, suma, m, v[1000], g[1000];
ifstream fin("psp.in");
ofstream fout("psp.out");
int main()
{
        fin >> n;
        fin >> v[1];


        for( i = 2;i <= n; ++i )
            {
                fin >> v[i];
            }
        s = 1;

        for ( i =1; i < n; ++i)
        {
                s = 0;
                if (v[i+1] < v[i])
                {
                    m = v[i + 1];
                    v[i + 1] = v[i];
                    v[i] = m;

                    s = 1;
                }
                if ( s == 0 ) break;
        }

        for ( i = 1; i <= n; ++i )
        {
                fin >> g[i];
        }
        s = 1;

        for ( i =1; i <= n; ++i)
        {
                s = 0;
                if (v[i+1] > v[i])
                {
                    m = v[i];
                    v[i] = v[i-1];
                    s = 1;
                }
                if ( s == 0 ) break;
        }
        }
        suma = v[1] + g[1];
        maxi = v[n] + g[1];
            fout << suma  << '\n';
            fout << maxi  << '\n';

            for (i = 1; i <= n ; ++i)
            {
                if ( v[n - i - 1] + g[i] == maxi )
                ++ nr;
            }

            fout << nr;





    return 0;
}
*/


#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#define F(i,j,n) for((i)=(j);(i<=(n));++(i))
using namespace std;
int i, n, k, nr, v[1000], g[1000] , j;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int main()
{

        fin >> n;

        for( i = 1; i <= n; ++i )

            fin >> v[i];

        sort(v + 1, v + n + 1);

        for( i = 1; i <= n; ++i )
        for( j = i + 1; j <= n; ++j )
        for( k = j + 1; k <= n; ++k )

            if (v[i] + v[j] >= v[k] && v[i] + v[k] >= v[j] && v[j] + v[k] >= v[i])
                ++nr;

            fout << nr;


    return 0;
}