import java.util.*;

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

        String plain = sc.nextLine();
        String[] str = plain.split("");

        for (int i=0;i<str.length;i++){
            // 大文字の時
            if(str[i].matches("[A-Z]")){
                str[i] = str[i].toLowerCase();
            }else {
                str[i] = str[i].toUpperCase();
            }
        }
		System.out.println(String.join("", str));
	}
}