I'm trying to find an algorithm for the following problem.
There are $5$ computer files with capacity $18$, $23$, $12$, $125$, $45$ MB respectively and there are $4$ hard disks with capacity $25$, $73$, $38$, $156$ MB. Each file has to be saved in one and only one disk. The cost of saving a file $i$ in a disk $j$ is the capacity of the disk $j$. Find an algorithm of saving files such that the total cost is minimum.
I think this problem can be reformulated as the Min-cost-max-flow problem. However, I don't know how to refomulate the condition "the sum of capacity of files in a disk cannot exceed the capacity of that disk". Can anyone help me? Thank you very much.