import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] input = sc.next().toCharArray();
		sc.close();
		for (int i = 0; i < input.length; i++) {
			if (Character.isUpperCase(input[i])) {
				System.out.print(Character.toLowerCase(input[i]));
			} else {
				System.out.print(Character.toUpperCase(input[i]));
			}
		}
		System.out.println();

	}
}