using namespace std;
int main()
{
unsigned long int i, x, y, z, counter = 1, a, b, c, ans=0;
int n;
cin >> n;
while(n>0)
{
unsigned long int arr[n];
for(i=0;i<n;i++)
{
cin >> arr[i];
}
for(x=0;x<=(n-3);x++)
{
for(y=(x+1);y<=(n-2);y++)
{
for(z=(y+1);z<=(n-1);z++)
{
a = arr[x];
b = arr[y];
c = arr[z];
while(counter <= 3)
{
if((a+b)<c)
{
ans++;
}
x = a;
a = b;
b = c;
c = x;
counter++;
}
counter = 1;
}
}
}
cout << ans << endl;
ans = 0;
cin >> n;
}
return 0;
}