#include <bits/stdc++.h>

using namespace std;
ifstream f("nrtri.in");
ofstream g("nrtri.out");
int v[801];
inline bool vrf(const int &x, const int &y, const int &z)
{
    return (x+y>=z and x+z>=y and y+z>=x);
}
int CB(int p, int q, int i, int j)
{
    int m;
    int nr=0;
    if(p<=q)
    {
        m=(p+q)/2;
        if(vrf(v[i],v[j],v[m])) {nr++;
        nr+=CB(p,m-1,i,j);
        nr+=CB(m+1,q,i,j);}
        else nr+=CB(p,m-1,i,j);
    }
    return nr;
}
int main()
{int n,i,j;
f>>n;
for(i=1;i<=n;i++)
f>>v[i];
sort(v+1,v+n+1);
int nr=0;
for(i=1;i<=n;i++)
    for(j=i+1;j<=n;j++)
    {
        nr+=CB(j+1,n,i,j);
    }
g<<nr;

    return 0;
}