import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String s = input.nextLine();

        for (char c : s.toCharArray()){
            if ('A' <= c && c <= 'Z'){
                System.out.print(Character.toLowerCase(c));
            }
            else if ('a' <= c && c <= 'z'){
                System.out.print(Character.toUpperCase(c));
            }
            else {
                System.out.print(c);
            }
        }
        System.out.println();
    }
}
/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