import java.util.Scanner;

class Y163{
    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 ch=s.charAt(i);
            if(Character.isLowerCase(ch)){
                ans+=Character.toUpperCase(ch);
            }else{
                ans+=Character.toLowerCase(ch);
            }
        }
        System.out.println(ans);
    }
}