Help me to fix error in this

Question

https://code.sololearn.com/cwMaVKbL4yyE/?ref=app

Answer 1

import java.util.Scanner;
And change order of class
First DRef
After DRef write Read

Answer 2

it is sololearn bug (I cant see dialogue window for input)
but you can avoid it if you change order of class in code to this:

class DRef {
//... first in order
}
class Read {
//... second in order, after DRef
}

Answer 3

Firs request on Scanner you must create in main void.