/*No.163 cAPSlOCK*/
import java.io.*;
public class No163 {
	public static void main(String[] args) {
		String password,w_password=new String(),moji;
		try(BufferedReader input =new BufferedReader(new InputStreamReader(System.in))){
			password=input.readLine();
			for(int i=0;i<password.length();i++){
				moji=password.substring(i, i+1);
				if(moji.codePointAt(0)>=65 &&moji.codePointAt(0)<=90){
					w_password+=moji.toLowerCase();
				}else if(moji.codePointAt(0)>=97 &&moji.codePointAt(0)<=122){
					w_password+=moji.toUpperCase();
				}
			}
			System.out.println(w_password);
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}