A worker can either split into two worker or build a block then dies. Both decisions cost some time.\n\nGiven a list `blocks`, where `blocks[i] = k` stands for `i-th` block\'s building time is `k`, and `cost` - the time cost of spliting one worker. Output the shortest time needed to build all blocks. \n\nInitially there is only one worker.\n\n**Example 1:**\n```\nInput: blocks = [1], cost = 1\nOutput: 1\nExplanation: The worker should build the block instead of spliting into two workers, the answer is 1\n```\n\n**Example 2:**\n```\nInput: blocks = [1, 2], cost = 5\nOutput: 7\nExplanation: The worker should split into two workers (costs 5 time unit), then build two blocks. The answer is 5 + max(1, 2) = 7.\nIf the first step is to build a block, the task won\'t be finished.\n```\n\n**Example 3:**\n```\nInput: blocks = [1, 2, 3], cost = 1\nOutput: 4\nExplanation: The worker splits into 2 workers, then one worker builds blocks[2], one splits, lastly we have three workers building blocks simultaneously.\nThe anwser is 1 + 1 + max(1, 2, 3 - 1) = 4\nThere is a 3 - 1 because one worker starts building blocks[2] = 3 from the second step, which lasts 1 time unit (i.e. the spliting time cost).\n```

A worker can either split into two worker or build a block then dies. Both decisions cost some time.\n\nGiven a list blocks, where blocks[i] = k stands for i-th