atcoder#ABC227E. [ABC227E] Swap

[ABC227E] Swap

Score : 500500 points

Problem Statement

Given is a string SS consisting of K, E, Y.

How many strings are there that can be obtained with at most KK swaps of two adjacent characters in SS?

Constraints

  • 2S302 \leq |S| \leq 30
  • 0K1090 \leq K \leq 10^9
  • SS consists of K, E, Y.

Input

Input is given from Standard Input in the following format:

SS

KK

Output

Print the answer.

KEY
1
3

With at most one swap, there are three strings that can be obtained: KEY, EKY, KYE.

KKEE
2
4

With at most two swaps, there are four strings that can be obtained: KKEE, KEKE, EKKE, KEEK.

KKEEYY
1000000000
90