import java.util.Scanner;

public class Main {

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

        StringBuilder builder = new StringBuilder();

        for (char c : s.toCharArray()) {
            if (Character.isUpperCase(c)) {
                builder.append(String.valueOf(c).toLowerCase());
            } else {
                builder.append(String.valueOf(c).toUpperCase());
            }
        }

        System.out.println(builder.toString());
    }
}