import java.util.Scanner;

/**
 * Toggling Cases
 */
public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        char[] charArray = scan.nextLine().toCharArray();
        scan.close();
        StringBuffer sb = new StringBuffer();
        for (char chara: charArray) {
            if (Character.isUpperCase(chara)) {
                sb.append(String.valueOf(chara).toLowerCase());
            } else {
                sb.append(String.valueOf(chara).toUpperCase());
            }
        }
        System.out.println(sb);
    }
}
/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