import java.util.ArrayList;
import java.util.Scanner;
/**
* Created by 莫文龙 on 2018/3/23.
*/
public class Main{
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int start = scanner.nextInt();
int end = scanner.nextInt();
int count = 0;
if (start <= 0 || end < start) {
throw new RuntimeException("输入的数据有误");
}
ArrayList<Integer> list = new ArrayList<>();
for (int i = start ; i <= end ; i ++) {
if (i == 1) continue;
if (i == 2) {
count ++;
list.add(2);
continue;
}
boolean flag = true;
for (int j = 2 ; j < i ; j ++) {
if (i % j == 0) {
//证明不是素数
flag = false;
break;
}
}
if (flag) {
count ++;
list.add(i);
}
}
System.out.println(start + "-" + end + "的素数个数为:" + count);
for (Integer i : list) {
System.out.print(i + ",");
}
}
}