在开发大型软件的漫长过程中，面对极其错综复杂的问题，人的主观认识不可能完全符合客观现实，与工程密切相关的各类人员之间的通信和配合也不可能完美无缺。-large software development in the long process, in the face of an extremely complex issue, the subjective understanding can not be completely in line with the objective reality

很完善的跳蚤市场商城功能设计和软件开发，符合需求-Flea Market Mall is the perfect functional design and software development, in line with demand

Were Tian Ji lives in nowadays, he will certainly laugh at himself. Even more, were he sitting in the ACM contest right now, he may discover that the horse racing problem can be simply viewed as finding the maximum matching in a bipartite graph. Draw