import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        StringBuffer sb = new StringBuffer();
        
        for(int i = 0; i < s.length(); i++) {
        	if(Character.isUpperCase(s.charAt(i)))
        		sb.insert(i, Character.toLowerCase(s.charAt(i)));
        	else 
        		sb.insert(i, Character.toUpperCase(s.charAt(i)));
        }

        System.out.println(sb.toString());
    }

}