import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
class Main {
public static String digMessage(Throwable e) {
String msg = e.getMessage();
if (msg == null && e.getCause() != null) {
return digMessage(e.getCause());
}
return msg;
}
}