CF447B DZY Loves Strings

Description

DZY loves collecting special strings which only contain lowercase letters. For each lowercase letter $ c $ DZY knows its value $ w_{c} $ . For each special string $ s=s_{1}s_{2}...\ s_{|s|} $ ( $ |s| $ is the length of the string) he represents its value with a function $ f(s) $ , where ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF447B/47a1fab5618b8aab7370048ef8382ed56e397765.png)Now DZY has a string $ s $ . He wants to insert $ k $ lowercase letters into this string in order to get the largest possible value of the resulting string. Can you help him calculate the largest possible value he could get?

Input Format

The first line contains a single string $ s (1

Output Format

Print a single integer — the largest possible value of the resulting string DZY could get.

Explanation/Hint

In the test sample DZY can obtain "abcbbc", $ value=1·1+2·2+3·2+4·2+5·2+6·2=41 $ .