import java.util.Scanner;
class Wandbox
{
    public static void main(String[] args)
    {
    	Scanner sc = new Scanner(System.in);
    	String s = sc.next();
    	String ans = "";
    	for (int i = 0; i < s.length(); i++) {
    		char c = s.charAt(i);
    		if (Character.isLowerCase(c)) {
    			ans += Character.toUpperCase(c);
    		}  else {
    			ans += Character.toLowerCase(c);
    		}
    	} 
    	
        System.out.println(ans);
    }
}