import java.util.Scanner;

public class No163{
	public static void main(String[]args){
		Scanner sc = new Scanner(System.in);

		String p = sc.nextLine();
		String P = "";

		for(int i=0;i<p.length();i++) {

			P +=Character.isUpperCase(p.charAt(i)) ?
					Character.toLowerCase(p.charAt(i)) :
					Character.toUpperCase(p.charAt(i));

		}

		System.out.println(P);



	}
}