sftp keyboard-interactrive bypass?

[William Murray]

   Hello all,
             I am trying to make a cron job copy files using sftp. 
Unfortunately the server only accepts password,keyboard-interactive
modes. So I would really like to redirect standard in.
   However, if I make a script like this:
   sftp  hhh at yyy <input.txt
it still requests the pasword from the keyboard. Is there any way to
get round this? I really cannot change the settings on the server.
            Thank you,
                   Bill