Sereja and Coat Rack

题意翻译

一共有 $n$ 个衣架 ，$m$ 个客人，每个客人来会选最便宜的衣架挂衣，旅店可以获得相应的钱，相反，衣架不够的话要给每个客人赔款 $d$ 元，问：旅店能赚多少钱？ traslated by kyron✅

题目描述

Sereja owns a restaurant for $ n $ people. The restaurant hall has a coat rack with $ n $ hooks. Each restaurant visitor can use a hook to hang his clothes on it. Using the $ i $ -th hook costs $ a_{i} $ rubles. Only one person can hang clothes on one hook. Tonight Sereja expects $ m $ guests in the restaurant. Naturally, each guest wants to hang his clothes on an available hook with minimum price (if there are multiple such hooks, he chooses any of them). However if the moment a guest arrives the rack has no available hooks, Sereja must pay a $ d $ ruble fine to the guest. Help Sereja find out the profit in rubles (possibly negative) that he will get tonight. You can assume that before the guests arrive, all hooks on the rack are available, all guests come at different time, nobody besides the $ m $ guests is visiting Sereja's restaurant tonight.

输入输出格式

输入格式

The first line contains two integers $ n $ and $ d $ $ (1<=n,d<=100) $ . The next line contains integers $ a_{1} $ , $ a_{2} $ , $ ... $ , $ a_{n} $ $ (1<=a_{i}<=100) $ . The third line contains integer $ m $ $ (1<=m<=100) $ .

输出格式

In a single line print a single integer — the answer to the problem.

输入输出样例

输入样例 #1

2 1
2 1
2

输出样例 #1

3

输入样例 #2

2 1
2 1
10

输出样例 #2

-5

说明

In the first test both hooks will be used, so Sereja gets $ 1+2=3 $ rubles. In the second test both hooks will be used but Sereja pays a fine $ 8 $ times, so the answer is $ 3-8=-5 $ .