Score : $300$ points
There are $N$ items in a shop. For each $i = 1, 2, \ldots, N$, the price of the $i$-th item is $A_i$ yen (the currency of Japan).
Takahashi has $K$ coupons.
Each coupon can be used on one item. You can use any number of coupons, possibly zero, on the same item. Using $k$ coupons on an item with a price of $a$ yen allows you to buy it for $\max\lbrace a - kX, 0\rbrace$ yen.
Print the minimum amount of money Takahashi needs to buy all the items.
Input is given from Standard Input in the following format:
$N$ $K$ $X$ $A_1$ $A_2$ $\ldots$ $A_N$
Print the answer.
5 4 7 8 3 10 5 13
12
By using $1$ coupon on the $1$-st item, $1$ coupon on the $3$-rd item, and $2$ coupons on the $5$-th item, Takahashi can:
for a total of $1 + 3 + 3 + 5 + 0 = 12$ yen, which is the minimum possible.
5 100 7 8 3 10 5 13
0
20 815 60 2066 3193 2325 4030 3725 1669 1969 763 1653 159 5311 5341 4671 2374 4513 285 810 742 2981 202
112