import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String str = sc.next();
		char[] ans = new char[str.length()];

		for (int i = 0; i < str.length(); i++) {
			if (Character.isUpperCase(str.charAt(i))) {
				ans[i] = Character.toLowerCase(str.charAt(i));
			} else {
				ans[i] = Character.toUpperCase(str.charAt(i));
			}
			System.out.print(ans[i]);
		}
	}
}