import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO ?????????????????????????????????????????????
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();

		StringBuilder answer = new StringBuilder();

		for (int i = 0; i < line.length(); i++) {
			String s = line.substring(i, i + 1);
			char cs = line.charAt(i);
			if (Character.isUpperCase(cs)) {
				answer.append(s.toLowerCase());
			} else {
				answer.append(s.toUpperCase());
			}

		}

		System.out.println(answer);

	}
}
/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