import java.util.Scanner;
public class M {
public static void main(String[] agrs){
Scanner scan =new Scanner(System.in);
System.out.println("请输入一个整数:" );
int num=scan.nextInt();
// boolean flag=false;
int i=2;
while(i<=num-1){
if (num%i==0) {
// flag = true;
break;
}
i++;
}
// if (flag){
if (i!=num){
System.out.println("不是素数");
}else
System.out.println("是素数");
}
}