CF1359E Modular Stability

We define $ x \bmod y $ as the remainder of division of $ x $ by $ y $ ( $ \% $ operator in C++ or Java, mod operator in Pascal). Let's call an array of positive integers $ [a_1, a_2, \dots, a_k] $ stable if for every permutation $ p $ of integers from $ 1 $ to $ k $ , and for every non-negative integer $ x $ , the following condition is met: $ (((x \bmod a_1) \bmod a_2) \dots \bmod a_{k - 1}) \bmod a_k = (((x \bmod a_{p_1}) \bmod a_{p_2}) \dots \bmod a_{p_{k - 1}}) \bmod a_{p_k} $ That is, for each non-negative integer $ x $ , the value of $ (((x \bmod a_1) \bmod a_2) \dots \bmod a_{k - 1}) \bmod a_k $ does not change if we reorder the elements of the array $ a $ . For two given integers $ n $ and $ k $ , calculate the number of stable arrays $ [a_1, a_2, \dots, a_k] $ such that $ 1 \le a_1 < a_2 < \dots < a_k \le n $ .

The only line contains two integers $ n $ and $ k $ ( $ 1 \le n, k \le 5 \cdot 10^5 $ ).

Print one integer — the number of stable arrays $ [a_1, a_2, \dots, a_k] $ such that $ 1 \le a_1 < a_2 < \dots < a_k \le n $ . Since the answer may be large, print it modulo $ 998244353 $ .