CF1559E Mocha and Stars
Description
Mocha wants to be an astrologer. There are $ n $ stars which can be seen in Zhijiang, and the brightness of the $ i $ -th star is $ a_i $ .
Mocha considers that these $ n $ stars form a constellation, and she uses $ (a_1,a_2,\ldots,a_n) $ to show its state. A state is called mathematical if all of the following three conditions are satisfied:
- For all $ i $ ( $ 1\le i\le n $ ), $ a_i $ is an integer in the range $ [l_i, r_i] $ .
- $ \sum \limits _{i=1} ^ n a_i \le m $ .
- $ \gcd(a_1,a_2,\ldots,a_n)=1 $ .
Here, $ \gcd(a_1,a_2,\ldots,a_n) $ denotes the [greatest common divisor (GCD)](https://en.wikipedia.org/wiki/Greatest_common_divisor) of integers $ a_1,a_2,\ldots,a_n $ .
Mocha is wondering how many different mathematical states of this constellation exist. Because the answer may be large, you must find it modulo $ 998\,244\,353 $ .
Two states $ (a_1,a_2,\ldots,a_n) $ and $ (b_1,b_2,\ldots,b_n) $ are considered different if there exists $ i $ ( $ 1\le i\le n $ ) such that $ a_i \ne b_i $ .
Input Format
N/A
Output Format
N/A
Explanation/Hint
In the first example, there are $ 4 $ different mathematical states of this constellation:
- $ a_1=1 $ , $ a_2=1 $ .
- $ a_1=1 $ , $ a_2=2 $ .
- $ a_1=2 $ , $ a_2=1 $ .
- $ a_1=3 $ , $ a_2=1 $ .