In the trading system, there are many kinds of futures contracts. The same futures contract has different months, which actually shows the due delivery month of varieties, such as sugar, and its delivery months are 1, 3, 5, 7, 9, 1 1. From the system, we can see that the pending orders of sugar are: sugar 1 105, sugar 1 107, sugar1/kloc-0. Among these contracts, we can judge which is the main contract, which is the near-month contract (near delivery) and which is the far-month contract from the corresponding month.