AT_fps_24_i スコア

You are given $ N $ distinct integers $ A_1, A_2, \dots, A_N $ . You will choose $ K $ of them. The **score** of a choice is defined as the product of the chosen integers. There are $ \binom{N}{K} $ possible ways to choose $ K $ integers. Find the sum of their scores, and output the result modulo $ 998244353 $ .

The input is given from standard input in the following format: > $ N $ $ K $ $ A_1 $ $ A_2 $ $ \dots $ $ A_N $

Print the answer.

### Sample Explanation 1 The possible ways to choose $ K $ integers and their scores are: - Choose $ A_1 = 2 $ and $ A_2 = 3 $ . The score is $ 2 \times 3 = 6 $ . - Choose $ A_1 = 2 $ and $ A_3 = 5 $ . The score is $ 2 \times 5 = 10 $ . - Choose $ A_2 = 3 $ and $ A_3 = 5 $ . The score is $ 3 \times 5 = 15 $ . ### Constraints - $ 1 \leq N \leq 2 \times 10^5 $ - $ 1 \leq K \leq N $ - $ 1 \leq A_i \leq 10^8 $ - If $ i \neq j $ , then $ A_i \neq A_j $ - All input values are integers