#include <fstream>
#include <algorithm>

using namespace std;

ifstream in("nrti.in");
ofstream out("nrtri.out");

const int L=16;
const int N = 100001;

int v[N];
int n;

int main()
{
    int n,nr=0,s, a, b;
    in>>n;
    for(int i=0;i<n;i++){
        in>>v[i];
    }
    sort(v,v+n);
    int r = 0;
    int pas = 1<<L;
	for(int i=n-1;i!=0;i--){
        for(int j=i-1;j!=0;j--){
            s=v[i]+v[j];
            a=n-1;
            b=j;
            while(pas>b){
                if(r+pas<=n && v[r+pas]<s){
                    r+=pas;
                    nr=r-b;
                }
                pas/=2;
            }
        }
	}
	out<<nr;
	return 0;
}