题目描述
Problem Statement
Given is a string S consisting of 0 and 1. Find the number of strings, modulo 998244353, that can result from applying the following operation on S between 0 and K times (inclusive):
- Choose a pair of integers $i, j (1\leq i < j\leq |S|)$ such that the i-th and j-th characters of S are 0 and 1, respectively. Remove the j-th character from S and insert it to the immediate left of the i-th character.
Input
Input is given from Standard Input in the following format:
S K
Output
Find the number of strings, modulo 998244353, that can result from applying the operation on S between 0 and K times (inclusive).
Constraints
- $1 \leq |S| \leq 300$
- $0 \leq K \leq 10^9$
- S consists of 0 and 1.
Sample Input 1
0101 1
Sample Output 1
4
Four strings, 0101, 0110, 1001, and 1010, can result.
Sample Input 2
01100110 2
Sample Output 2
14
Sample Input 3
1101010010101101110111100011011111011000111101110101010010101010101 20
Sample Output 3
113434815
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
0101 1
样例输出
4