import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
       String p = koko.next();
       char[] hai = p.toCharArray();
       for(int i=0; i<hai.length; i++){
           if(Character.isUpperCase(hai[i])){
               hai[i] = Character.toLowerCase(hai[i]);
           }else{
               hai[i] = Character.toUpperCase(hai[i]);
           }
       }
       System.out.println(String.valueOf(hai));
    }
}