import java.util.Scanner;

public class Puroguram{
	static Scanner scan= new Scanner(System.in);
	
	public static void main(String[] Args){
		String S =scan.next();
		
		StringBuilder S2 = new StringBuilder();
		for (int i=0; i<S.length(); i++){
			Character C1=S.charAt(i);
			if(Character.isUpperCase(C1)==true){
				S2.append(Character.toLowerCase(C1));
			}else{
				Character.toLowerCase(C1);
				S2.append(Character.toUpperCase(C1));
			}
		}
		System.out.println(S2);
	}
}