import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		String s = sc.next(), ans = "";
		for(int i = 0; i < s.length(); i++){
			if(s.charAt(i) >= 'a'){
				ans += s.charAt(i)-'a'+'A';
			} else {
				ans += s.charAt(i)-'A'+'a';
			}
		}
		System.out.println(ans);
	}
}