import java.util.Scanner;
 
 public class Main {
     public static void main(String[] args) {
         Scanner sc = new Scanner(System.in);

         String s = sc.nextLine();
         String ans = "";
    
         for(int i=0; i<s.length(); i++){
             if(Character.isUpperCase(s.charAt(i))){
                char A = s.charAt(i);
                A = Character.toLowerCase(s.charAt(i));
                ans += A;

             }else{
                char A = s.charAt(i);
                A = Character.toUpperCase(s.charAt(i));
                ans += A;
             }
         }
         
         System.out.println(ans);
     }
 }