import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char a = sc.next().charAt(0);
        if (a >= 'A' && a <= 'Z')
            System.out.println((char) (a + 32));
        else if (a >= 'a' && a <= 'z')
            System.out.println((char) (a - 32)) ;
        else
            System.out.println((int)a);
    }
}