import java.util.*;
class Yukico163 {
	public static void main(String[] args) {
		Scanner stdio = new Scanner(System.in);
		String s = stdio.next();
		String ans ="";
		for(int i=0; i<s.length(); i++) {
			if(Character.isUpperCase(s.charAt(i))) {
				ans =ans+Character.toLowerCase(s.charAt(i));
			} else {
				ans =ans+Character.toUpperCase(s.charAt(i));
			}
		}
		System.out.println(ans);
	}
}