You are given integers n, m, and k. There are two logs of lengths n and m units, which need to be transported in three trucks where each truck can carry one log with length at most k units. You may cut the logs into smaller pieces, where the cost of cutting a log of length x into logs of length len1 and len2 is cost = len1 * len2 such that len1 + len2 = x. Return the minimum total cost to distribute the logs onto the trucks. If the logs don't need to be cut, the total cost is 0.