8526: Boss

NIO is a big boss. He will now dispatch his N employees to K cities. And he must send exactly ei employees to the i-th city. 

NIO has no redundant employees which means,

The cost of sending the i-th employee to the j-th city is c_i,j. NIO wants to know the minimum cost of the dispatch.

The first line contains two integers N(1≤N≤10⁵) and K(1≤K≤10) --- the number of employees and the number of the cities.
The second line contains K integers e_i(1≤e_i≤n) --- the number of employees for i-th city.
The following N lines each contain K integers cij(0≤c_i,j≤10⁵) --- the cost of sending the i-th employee to the j-th city.

One integer represent the minimum cost.

5 2
1 4
1 1 
4 3 
4 5 
2 1 
3 2

11