import java.util.Scanner;
public class Main {
    public static void main (String[] args) {
	Scanner scan = new Scanner(System.in);
	String input = scan.nextLine();
	char[] inputArray = new char[input.length()];
	for (int i = 0; i < input.length(); i++) {
	    char alpabet = input.charAt(i);
	    if (Character.isUpperCase(alpabet)) {
		inputArray[i] = Character.toLowerCase(alpabet);
	    } else if (Character.isLowerCase(alpabet)){
		inputArray[i] = Character.toUpperCase(alpabet);
	    } else {
		inputArray[i] = alpabet;
	    }
	}
	System.out.println(String.valueOf(inputArray));
    }
}
/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