Shows uppercase and lowercase characters

import java.util.Scanner;

public class project {
     public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);
            String up = "";
            String down = "";
            System.out.print("Give a string: ");
            String x = sc.nextLine();
            int z = x.length();
            for (int y = 0; y < z; y++) {
                if (Character.isUpperCase(x.charAt(y))) {
                    char w = x.charAt(y);
                    up = up + w;
                } else if (Character.isLowerCase(x.charAt(y))) {
                    char w = x.charAt(y);
                    down = down + w;
                }
            }
            System.out.println("The uppercase characters are: " + up);
            System.out.println("The lowercase characters are: " + down);
        }
}