import java.util.Scanner;

public class Back_2744 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //given
        String str=sc.nextLine();
        char arr[] = new char[str.length()];
        //when
        for(int i=0;i<str.length();i++){
            if(65<=str.charAt(i) && str.charAt(i)<=90){
                arr[i]=(char)(str.charAt(i)+32);

            }
            else if(97<=str.charAt(i) && str.charAt(i)<=122){
                arr[i]=(char)(str.charAt(i)-32);

            }
        }
        //then
        System.out.println(arr);


    }
}