Test Taking     teststr.X

Farmer John has to take his annual farming license test. The test
comprises N (1 <= N <= 1,000,000) true/false questions. After FJ's
dismal performance on last year's test Bessie wishes to help him.

Bessie has inside information that the number of questions whose
answer is true will be one of t_1, t_2, t_3,..., or t_K (0 <= t_i
<= N; 0 <= K <= 10,000) -- even though Bessie has no information
about any answer to any specific question. Bessie wants to know the
best score that FJ is guaranteed achieve by exploiting this information
carefully, even if he doesn't know the actual answers to any test
questions.

To demonstrate Bessie's idea, consider a license test with N=6
questions where Bessie knows that the number of questions with the
answer 'true' is either 0 or 3. FJ can always get at least 3 answers
correct using logic like this: If FJ answers 'false' on every
question and there are 0 questions with the answer 'true' then he
will get all 6 correct. If there are 3 questions with the answer
'true' then he will get 3 answers correct. So as long as he marks
every answer as 'false' he is guaranteed to get at least 3 correct
without knowing any answer to the test questions.

On the other hand, consider what happens if FJ chooses an inferior
strategy: he guesses that some 3 answers are 'true' and the other
3 are 'false'. If it turns out that NO answers are 'true' then FJ
will get 3 answers correct, the ones he guessed were false. If 3
answers are 'true' then FJ could get as few as 0 answers correct.
If he answered incorrectly on all 3 of that answers for which he
guessed 'true', and the other 3 (for which he guessed 'false') are
true, then he gets 0 correct answers. Even though FJ could get 3
correct in this case by guessing 'false' every time, he can not
always guarantee even 1 correct by guessing some 3 answers as 'true',
so this strategy can not guarantee getting any answer correct. FJ
should use the previous paragraph's strategy.

Given Bessie's inside information, determine the number of answers
FJ can always get correct using this information assuming he uses
it optimally.

PROBLEM NAME: teststr

INPUT FORMAT:

* Line 1: Two space-separated integers: N and K

* Lines 2..K+1: Line i+1 contains a single integer: t_i

SAMPLE INPUT:

6 2
0
3

OUTPUT FORMAT:

* Line 1: A single integer, the best score FJ is guaranteed to achieve

SAMPLE OUTPUT:

3