import java.io.*;  

public class Translate {
    /** The String S, but with all characters that occur in FROM changed
     *  to the corresponding characters in TO. FROM and TO must have the 
     *  same length. */
    static String translate (String S, String from, String to) {
        char[] buffer = new char[S.length ()];
        // NOTE: This try {...} catch is a technicality to keep Java happy.
        try {
            throw new IOException (); // REPLACE THIS LINE WITH THE RIGHT ANSWER.
        } catch (IOException e) { return null; }
    }
    // REMINDER: translate must
    //  a. Be non-recursive
    //  b. Contain only 'new' operations, and ONE other method call, and no
    //     other kinds of statement (other than return).
    //  c. Use only the library classes String, and anything containing
    //     "Reader" in its name (browse the on-line documentation).
}