import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        String [] S=sc.next().split("");
        String result="";

        for(int i=0; i<S.length; i++){
            if( S[i].matches( "[a-z]+" ) ){
                result=S[i].toUpperCase();
        System.out.print(result);
            }else if(S[i].matches("[A-Z]")){
                result=S[i].toLowerCase();
        System.out.print(result);

            }
        }
            sc.close();
		}
    }