import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)){
			String line = sc.nextLine();
			String answer = "";
			int length = line.length();
			for(int i = 0; i < length; i++){
				char ch = line.charAt(i);
				if(Character.isUpperCase(ch)){
					ch = Character.toLowerCase(ch);
					System.out.print(ch);
				}else if(Character.isLowerCase(ch)){
					ch = Character.toUpperCase(ch);
					System.out.print(ch);
				}else{
					System.out.print(ch);
				}
			}
			System.out.println();
		}
	}
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz