1709  Old Printer
Time Limit : 2 Second
Memory Limit : 128 MB
Submission: 37
Solved: 9
 Description
Zero has an old printer that doesn't work well sometimes. As it is antique, he still like to use it to print articles. But it is too old to work for a long time and it will certainly wear and tear, so Zero use a cost to evaluate this degree.
One day Zero want to print an article which has N words and M lines, and each word i has a cost Ci to be printed. Also, Zero know that print k words in one line will cost
Now Zero want to know the minimum cost in order to arrange the article perfectly.
 Input
There are many test cases. For each test case, There are two numbers N and M in the first line (0 ≤ n ≤ 10000, 0 ≤ M ≤ 500). Then, there are N numbers in the next 2 to N + 1 lines. The i+1line is Ci (1<=Ci<=10000). Input are terminated by EOF.
 Output
A single number, meaning the mininum cost to print the article.
 sample input

Sample input 1 5 2 5 9 5 7 5 Sample input 2 2 3 5 7
 sample output

Sample output 1 485 Sample output 2 74
 hint
 source
 liaolingyun