import java.util.Scanner;

public class No163 {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String password = s.next();
        char[] actual = new char[password.length()];
        for (int i = 0; i < password.length(); i++) {
            char c = password.charAt(i);
            if (Character.isUpperCase(c)) {
                actual[i] = Character.toLowerCase(c);
            } else {
                actual[i] = Character.toUpperCase(c);
            }
        }
        System.out.println(actual);
    }
}