Easy Problem

题意翻译

给你一个长为 $n$ 的字符串 $s$ 以及 $a_{1..n}$，删去第 $i$ 个字符的代价为 $a_i$，你需要删去一些字符（如果一开始就符合条件当然可以不删）使得剩下的串中不含子序列 "hard"，求最小代价。 子序列不需要连续。

题目描述

Vasya is preparing a contest, and now he has written a statement for an easy problem. The statement is a string of length $ n $ consisting of lowercase Latin latters. Vasya thinks that the statement can be considered hard if it contains a subsequence hard; otherwise the statement is easy. For example, hard, hzazrzd, haaaaard can be considered hard statements, while har, hart and drah are easy statements. Vasya doesn't want the statement to be hard. He may remove some characters from the statement in order to make it easy. But, of course, some parts of the statement can be crucial to understanding. Initially the ambiguity of the statement is $ 0 $ , and removing $ i $ -th character increases the ambiguity by $ a_i $ (the index of each character is considered as it was in the original statement, so, for example, if you delete character r from hard, and then character d, the index of d is still $ 4 $ even though you delete it from the string had). Vasya wants to calculate the minimum ambiguity of the statement, if he removes some characters (possibly zero) so that the statement is easy. Help him to do it! Recall that subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements.

输入输出格式

输入格式

The first line contains one integer $ n $ ( $ 1 \le n \le 10^5 $ ) — the length of the statement. The second line contains one string $ s $ of length $ n $ , consisting of lowercase Latin letters — the statement written by Vasya. The third line contains $ n $ integers $ a_1, a_2, \dots, a_n $ ( $ 1 \le a_i \le 998244353 $ ).

输出格式

Print minimum possible ambiguity of the statement after Vasya deletes some (possibly zero) characters so the resulting statement is easy.

输入输出样例

输入样例 #1

6
hhardh
3 2 9 11 7 1

输出样例 #1

5

输入样例 #2

8
hhzarwde
3 2 6 9 4 8 7 1

输出样例 #2

4

输入样例 #3

6
hhaarr
1 2 3 4 5 6

输出样例 #3

0

说明

In the first example, first two characters are removed so the result is ardh. In the second example, $ 5 $ -th character is removed so the result is hhzawde. In the third example there's no need to remove anything.