import java.util.Scanner;

public class No163 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();

        String result = "";

        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);

            if (c < 'a') {
                result += String.valueOf(s.charAt(i)).toLowerCase();
            } else {
                result += String.valueOf(s.charAt(i)).toUpperCase();
            }
        }

        System.out.println(result);

        sc.close();
    }

}