AT_past202306_i 最大公約数の最大値

You are given $ N $ integers $ A_1, A_2, \ldots, A_N $ . Consider choosing $ K $ of them. Find the maximum possible greatest common divisor of the chosen integers.

The input is given from Standard Input in the following format: > $ N $ $ K $ $ A_1 $ $ A_2 $ $ \ldots $ $ A_N $

Print the maximum possible greatest common divisor.

### Sample Explanation 1 If you choose $ 2 $ and $ 4 $ , the greatest common divisor will be $ 2 $ , which is the maximum. ### Constraints - $ 1 \leq K \leq N \leq 5 \times 10^5 $ - $ 1 \leq A_i \leq 10^6 $ - All input values are integers.