import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] text = sc.nextLine().toCharArray();
		
		for(int i=0; i<text.length; i++) {
			if(Character.isUpperCase(text[i])) {
				text[i] = Character.toLowerCase(text[i]);
			} else {
				text[i] = Character.toUpperCase(text[i]);
			}
		}
		
		System.out.println(text);
	}

}
/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