AT_abc392_b [ABC392B] Who is Missing?

You are given a sequence of $ M $ integers $ A = (A_1, A_2, \dots, A_M) $ . Each element of $ A $ is an integer between $ 1 $ and $ N $ , inclusive, and all elements are distinct. List all integers between $ 1 $ and $ N $ that do not appear in $ A $ in ascending order.

The input is given from Standard Input in the following format: > $ N $ $ M $ $ A_1 $ $ A_2 $ $ \dots $ $ A_M $

Let $ (X_1, X_2, \dots, X_C) $ be the sequence of all integers between $ 1 $ and $ N $ , inclusive, that do not appear in $ A $ , listed in ascending order. The output should be in the following format: > $ C $ $ X_1 $ $ X_2 $ $ \dots $ $ X_C $

### Sample Explanation 1 Here, $ A=(3,9,2) $ . The integers between $ 1 $ and $ 10 $ that do not appear in $ A $ , listed in ascending order, are $ 1,4,5,6,7,8,10 $ . ### Sample Explanation 2 No integer between $ 1 $ and $ 6 $ is missing from $ A $ . In this case, print `0` on the first line and leave the second line empty. ### Constraints - All input values are integers. - $ 1 \le M \le N \le 1000 $ - $ 1 \le A_i \le N $ - The elements of $ A $ are distinct.