import java.io.IOException;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws IOException {

		new Main().run();
	}

	private void run() throws IOException {
		Scanner scanner = new Scanner(System.in);
		String str = scanner.next();
		str.chars()
				.mapToObj(i -> (char) i)
				.map(s -> s >= 'a' ? Character.toUpperCase(s) : Character
						.toLowerCase(s)).forEach(System.out::print);
		System.out.println();

	}
}