import java.util.Scanner;

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