import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String S = reader.readLine();
        StringBuilder builder =  new StringBuilder();
        for (int i = 0; i < S.length(); i++) {
            if(Character.isUpperCase(S.charAt(i))){
                builder.append(Character.toLowerCase(S.charAt(i)));
            } else {
                builder.append(Character.toUpperCase(S.charAt(i)));
            }
        }
        System.out.println(builder.toString());
    }
}