Console input age, depending on age output different hints

Code:

Import Java.util.Scanner;

public class Nianling {

public static void Main (string[] args) {
TODO auto-generated method stubs
Scanner sc=new Scanner (system.in);
System.out.print ("Please enter Age:");
Double age=sc.nextdouble ();
if (age%1==0&age>=0&age<=135)
{
int a= (int) age;
if (a<21)
{
System.out.println ("Children");
}
else if (a<31)
{
SYSTEM.OUT.PRINTLN ("Youth");
}
else if (a<51)
{
System.out.println ("Middle-aged");
}
Else
{
SYSTEM.OUT.PRINTLN ("elderly");
}
}
Else
{
System.out.println ("Please enter the correct age");
}

}

}

Console input age, depending on age output different hints