题目描述
Problem Statement
Given is a string S consisting of K, E, Y.
How many strings are there that can be obtained with at most K swaps of two adjacent characters in S?
Input
Input is given from Standard Input in the following format:
S
K
Output
Print the answer.
Constraints
- $2 \leq |S| \leq 30$
- $0 \leq K \leq 10^9$
- S consists of K, E, Y.
Sample Input 1
KEY
1
Sample Output 1
3
With at most one swap, there are three strings that can be obtained: KEY, EKY, KYE.
Sample Input 2
KKEE
2
Sample Output 2
4
With at most two swaps, there are four strings that can be obtained: KKEE, KEKE, EKKE, KEEK.
Sample Input 3
KKEEYY
1000000000
Sample Output 3
90
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
KEY
1
样例输出
3