#include <bits/stdc++.h>
using namespace std;
int a[110],n,x,c; 
int main(){
    cin>>n;
    int i;
    for(i = 0;i < n;i++){
        cin>>a[i];
    }
    cin>>x;
    for(i = 0;i < n;i++){
        if(a[i] >= x - 5 && a[i] <= x + 5){
            c++;
        }
    } 
    cout<<c;
}
/**************************************************************
	Problem: 1964
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:26 ms
	Memory:2072 kb
****************************************************************/