JaeHyeonKim19

import java.io.*;
import java.util.*;

public class Main {
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		int gap = Math.abs(Integer.parseInt(st.nextToken()) - Integer.parseInt(st.nextToken()));
		int count = 0;
		while(gap >= 8) {
			count++;
			gap = Math.abs(gap - 10);
		}
		while(gap >= 3) {
			count++;
			gap = Math.abs(gap - 5);
		}
		while(gap != 0) {
			count++;
			gap -= 1;
		}
		System.out.print(count);
	}
}