import java .util.Scanner;
public class Main {
public static void main(String[] args) {
while (true) {
System.out.println("請輸入要判斷的年齡");
Scanner in = new Scanner(System.in);
int age = in.nextInt();
if (age < 0) {
System.out.println("輸入有誤,重新輸入");
continue;
}
if (age >= 0 && age <= 18) {
System.out.println("少年");
break;
}
if (age >= 19 && age <= 28) {
System.out.println("少年");
break;
}
if (age >= 29 && age <= 55) {
System.out.println("中年");
break;
} else {
System.out.println("老年");
break;
}
}
}
}