import java.util.Arrays;
import java.util.Scanner;

public class 漂流船问题 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String[] strings = sc.nextLine().split(" ");
int capacity = sc.nextInt();
int[] weights = new int[strings.length];
for (int i = 0;i<strings.length;i++){
weights[i] = Integer.parseInt(strings[i]);
}
Arrays.sort(weights);
int l = 0;
int r = weights.length-1;
int ans = 0;
while (l<r){
if (weights[l]+weights[r]<=capacity){
l++;
r--;
}else {
r--;
}
ans++;
}
if (l==r){
ans++;
}
System.out.println(ans);

}

}