# Problem B: Safebreaker

**Input file:** `safe.in`

**Output file:** `safe.out`

We are observing someone playing a game similar to Mastermind (TM).
The object of this game is to find a secret code by intelligent
guesswork, assisted by some clues. In this case the secret code is
a 4-digit number in the inclusive range from 0000 to 9999, say "3321".
The player makes a first random guess, say "1223" and then, as for
each of the future guesses, gets a clue telling how close the guess is.
A clue consists of two numbers: the number of correct digits (in this
case, one: the "2" at the third position) and the additional number of
digits guessed correctly but in the wrong place (in this case, two:
the "1" and the "2"). The clue would in this case be: "1/2". For the
guess "1110", the clue would be "0/1", since there are no correct
digits and only one misplaced digit. (Notice that there is only one
digit 1 misplaced.)

Write a program that, given a set of guesses and corresponding clues,
tries to find the secret code.

## Input specification

The first line of input specifies the number of test cases (`N`)
your program has to process. Each test case consists of a first line
containing the number of guesses `G` (0 <= `G` <= 10),
and `G` subsequent lines consisting of exactly 8 characters:
a code of four digits, a blank, a digit indicating the number of correct
digits, a "/", and a digit indicating the number of correct but misplaced
digits.

## Output specification

For each test case, the output contains a single line saying either:

`impossible`

if there is no code consistent with all guesses.

`n`

, where `n` is the secret code, if
there is exactly one code consistent with all guesses.

`indeterminate`

if there is more than one code which is
consistent with all guesses.

## Sample input

4
6
9793 0/1
2384 0/2
6264 0/1
3383 1/0
2795 0/0
0218 1/0
1
1234 4/0
1
1234 2/2
2
6428 3/0
1357 3/0

## Sample output

3411
1234
indeterminate
impossible