#include <bits/stdc++.h>
using namespace std;
long long a[100200];
int n,i,j,k,u=0;
int main(){
	ifstream cin("nrtri.in");
	ofstream cout("nrtri.out");
	cin>>n;
	for (i=0;i<n;i++)
	cin>>a[i];
	sort (a,a+n);
	
	for (i=0;i<n;i++){   
	if (a[i]+a[i+1]>=a[i+2] && a[i]+a[i+2]>=a[i+1] && a[i+1]+a[i+2]>= a[i])
	{
	u++;
	}
}  
cout<<u;
	
	return 0;
}