#include<stdio.h>
using namespace std;

int v[8001],a[10];
int main()
{
FILE *f=fopen("nrtri.in","r"), *g=fopen("nrtri.out","w");

	int i,j,k,n,tri=0,ok;
	fscanf(f,"%d",&n);
	for(i=1;i<=n;i++)
		fscanf(f,"%d",&v[i]);
	for(i=1;i<=n/2;i++)
		for(j=1;j<=n/2;j++)
			if(i!=j)
				for(k=1;k<=n;k++)	
					if((j!=k)&&(i!=k))
					{
					a[1]=v[i];	a[2]=v[j];	a[3]=v[k];
					ok=1;
					if( ( a[1] > a[2] +a[3 ] ) ||  ( a[2] > a[1] +a[3 ])  || (  a[3] > a[2] +a[1] ))
						ok=0;
					if(ok==1) tri++;
				
					}
				
				
				
	fprintf(g,"%d\n",tri);

return 0;
}