#D10298. Shift
Shift
Shift
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
and1
, respectively. Remove the j-th character from S and insert it to the immediate left of the i-th character.
Constraints
- 1 \leq |S| \leq 300
- 0 \leq K \leq 10^9
- S consists of
0
and1
.
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).
Examples
Input
0101 1
Output
4
Input
01100110 2
Output
14
Input
1101010010101101110111100011011111011000111101110101010010101010101 20
Output
113434815
inputFormat
Input
Input is given from Standard Input in the following format:
S K
outputFormat
Output
Find the number of strings, modulo 998244353, that can result from applying the operation on S between 0 and K times (inclusive).
Examples
Input
0101 1
Output
4
Input
01100110 2
Output
14
Input
1101010010101101110111100011011111011000111101110101010010101010101 20
Output
113434815
样例
0101 1
4