#I'm always right


Given the following input:

 - A number consisting of decimal digits, the `guess`

 - A number consisting of decimal digits, the `answer`

You are to output a single natural number, the `base`, such that when you interpret the `guess` as a number in the base `base`, the distance between `guess` and `answer` is smaller than for any other choice of `base`. 

To be clear, 

- `answer` is interpreted as base 10

- `guess` is interpreted as base `base`

- distance means absolute value

- The `base` must be greater than the largest digit used. I.e. if `6` appears in the `guess`, you cannot output a base smaller than `7` because any base smaller than 7 does not use the symbol `6`. 

**Motivation and Example**

Your friend asks you a question like "What's the population of New York City?" 

You have no clue, so you make a guess "1,400,000 people", you say.

 He says "You're an idiot, the population is 8,550,405. You were so far off." 

You then do some quick math in your head and say, "I wasn't that far off, I didn't realize you wanted base 10. I was using base 14. In base 10, I said 9,680,832, which wasn't that bad of a guess"

In this example

 guess = 1400000
 answer = 8550405
 base = 14

**Test cases**

Eventually maybe.