import java.util.Scanner;

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

/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