import java.util.Scanner;

public class CapsLock {

    public static void main(String[] args) {
        
        Scanner scanner = new Scanner(System.in);
        StringBuilder str = new StringBuilder();
        str.append(scanner.next());
      
        char c;
        
        for(int i=0;i<str.length();i++){
            
            c = str.charAt(i);
            
            if(Character.isUpperCase(c)){
                str.setCharAt(i, Character.toLowerCase(c));
            }else{
                str.setCharAt(i, Character.toUpperCase(c));
            }
            
        }
        
        System.out.println(str);
        
    }
    
}