#include<cstdio>
#include<algorithm>
using namespace std;
int n,v[5000];
void read()
{
    freopen("nrtri.in","r",stdin);
    freopen("nrtri.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&v[i]);
}

bool comp(int a, int b)
{
    return a<b;
}

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

void rez()
{
    sort(v+1,v+n+1,comp);
    //for(int i=1;i<=n;i++)
    //    printf("%d ",v[i]);
    //printf("\n");
    int num=0,i,j,k;
    for(i=1;i<=n;i++)
        for(j=i+1;j<=n;j++)
            for(k=j+1;k<=n;k++)
                if(triunghi(v[i],v[j],v[k]))
                {
                    num++;
                    //printf("%d %d %d %d %d %d\n",i,j,k,v[i],v[j],v[k]);
                }
    printf("%d\n",num);
}

int main()
{
    read();
    rez();
    return 0;
}