package inflearn;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;
import java.util.StringTokenizer;
/*
* 송아지 찾기 1(BFS : ìƒíƒœíŠ¸ë¦¬íƒìƒ‰)
* */
public class Problem7_08 {
int result = 0;
int[] distance = {-1, 1, 5};
boolean[] visited;
Queue queue = new LinkedList<>();
public int BFS(int s, int e) {
visited = new boolean[10001];
visited[s] = true;
queue.offer(s);
int level = 0;
while(!queue.isEmpty()) {
int length = queue.size();
for (int i = 0; i < length; i++) {
int num = queue.poll();
// if (num == e) {
// return level;
// }
for (int j = 0; j < distance.length; j++) {
int nx = num + distance[j];
if (nx == e) return level+1;
if (nx >= 1 && nx <= 10000 && visited[nx] == false) {
visited[nx] = true;
queue.offer(nx);
}
}
}
level++;
}
return 0;
}
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
int s = Integer.parseInt(st.nextToken());
int e = Integer.parseInt(st.nextToken());
Problem7_08 problem = new Problem7_08();
problem.result = problem.BFS(s, e);
System.out.println(problem.result);
}
}