import java.util.Scanner;

public class Capslock {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		StringBuilder str = new StringBuilder(s.nextLine());
		s.close();
		
		for(int i = 0;i < str.length();i++){
			char c = str.charAt(i);
			if(Character.isUpperCase(c)){
				str.setCharAt(i,Character.toLowerCase(c));
			}else{
				str.setCharAt(i, Character.toUpperCase(c));
			}
		}
		System.out.println(str);

	}

}