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 = str.toCharArray();

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