import java.io.*;
public class Main {

	public static void main(String[] args) throws IOException{
		String s;
		BufferedReader kbd = new BufferedReader(new InputStreamReader(System.in));
			s = kbd.readLine();
			for(int i = 0; i < s.length(); i++){
				if(Character.isUpperCase(s.charAt(i)))
					System.out.print(Character.toLowerCase(s.charAt(i)));
				else if(Character.isLowerCase(s.charAt(i)))
					System.out.print(Character.toUpperCase(s.charAt(i)));
				else
					System.out.print(s.charAt(i));
			}
				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