import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        String [] arr = S.split("");
        String s = "";
        for(int i=0; i<S.length(); i++){
            if( S.charAt(i)>='A' && 'Z'>=S.charAt(i)){
                s = s + arr[i].toLowerCase();
            }else{
                s = s + arr[i].toUpperCase();
            }
        }
        System.out.println(s);
    }
}