题目描述
Problem Description
Let $x = 40^{76^{93}}$. There are $n$ points on a plane, with the $i$-th point located at coordinates $(x^i, 0)$.
Perform $m$ operations, where each operation selects two points $A$ and $B$, rotates $A$ 60 degrees clockwise around $B$, and then removes $B$.
Determine the number of possible positions for the center of mass of the remaining points, modulo $998244353$.
Constraints: $2 \le n \le 407693$, $1 \le m \le n-1$.
Input Format
A single line containing two integers $n$ and $m$.
Output Format
A single line containing the answer modulo $998244353$.
Sample Input and Output
Sample Input #1
3 2
Sample Output #1
12
Sample Input #2
4 3
Sample Output #2
60
Sample Input #3
22 21
Sample Output #3
478037653
Sample Input #4
407693 333333
Sample Output #4
971291318
Notes
This problem consists of a single subtask, and you must pass all data points to receive points.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
3 2
样例输出
12