import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            String line = sc.nextLine();
            String answer = "";
            int length = line.length();
            for (int i = 0; i < length; i++) {
                char ch = line.charAt(i);
                if (Character.isLowerCase(ch)) {
                    ch=Character.toUpperCase(ch);
                } else {
                    ch=Character.toLowerCase(ch);
                }
                answer+=ch;
            }
            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