import java.util.Scanner;

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

        String s = sc.nextLine();
        char[] chars = new char[s.length()];

        for(int i=0; i<s.length(); i++) {
        	char c = s.charAt(i);
        	if(Character.isUpperCase(c)) {
        		chars[i] = Character.toLowerCase(c);
        	} else if(Character.isLowerCase(c)) {
        		chars[i] = Character.toUpperCase(c);
        	} else {
        		chars[i] = c;
        	}
        }

        for(int i=0; i<s.length(); i++) {
        	System.out.print(chars[i]);
        }
        System.out.println();
	}
}