import java.util.Scanner;
public class Digit
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
System.out.println("請輸入字符串：");
String str = sc.nextLine();
String str1 = new String();
System.out.println("輸入的字符串為：" + str);
for (int i=0;i<str.length();i++)
{
if (Character.isDigit(str.charAt(i)))
{
char c = str.charAt(i);
System.out.print(c);
}
}
}
}