题目描述
DZY loves collecting special strings which only contain lowercase letters. For each lowercase letter c DZY knows its value wc. For each special string s = s1s2... s|s| (|s| is the length of the string) he represents its value with a function f(s), where
$$f(s) = \sum_{i=1}^{|s|} (w_{s_i} \cdot i).$$
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
The first line contains a single string s (1 ≤ |s| ≤ 103).
The second line contains a single integer k (0 ≤ k ≤ 103).
The third line contains twenty-six integers from wa to wz. Each such number is non-negative and doesn't exceed 1000.
Output
Print a single integer — the largest possible value of the resulting string DZY could get.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the test sample DZY can obtain "abcbbc", value = 1·1 + 2·2 + 3·2 + 4·2 + 5·2 + 6·2 = 41.