import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc =new Scanner(System.in);
		String a = sc.nextLine();
		
		String xx="";
		for(int i=0;i<a.length();i++){
			char m;
			m=a.charAt(i);
			if(m>='a'&&m<'z'){
				xx=xx+m;
			}
			
		}
		String dx="";
		for(int i=a.length()-1;i>=0;i--){
		
		char z=a.charAt(i);
			if(z>='A'&&z<='Z'){
				dx=dx+z;
			}
		}
		System.out.println(dx+""+xx);
	    

		
		
		
		
		sc.close();
	}
	
	
}
/**************************************************************
	Problem: 1569
	User: admin
	Language: Java
	Result: Accepted
	Time:2219 ms
	Memory:43356 kb
****************************************************************/