import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int n = s.length();
		String ans = "";
		for(int i = 0 ; i < n ; i++) {
			ans += Character.isUpperCase(s.charAt(i)) ? Character.toLowerCase(s.charAt(i)) : Character.toUpperCase(s.charAt(i));
		}
		System.out.println(ans);
 	}
}