#include<cstdio>
#include<algorithm>
using namespace std;
int main ()
{
   freopen("nrtri.in","r",stdin);
   freopen("nrtri.out","w",stdout);
   int i,n,a,b,c,k;
    scanf("%d",&n);
    int v[n+1];
    k=0;
    for(i=0;i<n;i++) scanf("%d",&v[i]);
    sort(v,v+n);
    for(a=0;a<n-2;a++)
    {
        for(b=a+1;b<n-1;b++)
        {
            for(c=b+1;c<n;c++)
            {
                if(v[a]<=v[b]+v[c] && v[b]<=v[a]+v[c] && v[c]<=v[a]+v[b])
                {
                    k++;
                }
            }
        }
    }
    scanf("%d",&k);

}