Jonathan and Peter are playing the Number Game. It is a game where one of the players try to guess a four-digit number that is secretly written by a "number dealer" in the least number of guesses possible. There are a few rules to consider though.
Jonathan dealt a four digit number to Peter. Peter guessed for the number four times, and obtained the following results:
What is the smallest number that Jonathan could have written?
Note: This problem is original.