Fourth:

2019 is decomposed into the sum of 3 different positive integers, and requires every positive integer is not package
With Numbers 2 and 4, how many different kinds of decomposition method?
Pay attention to the exchange of three integer order is regarded as the same way, such as 1000 + 1001 + 18 and
1001 + 1000 + 18 is regarded as the same,

Thinking: please scope does not contain the sum of the number of 2 and 4 (the find string==string: : npos)

The answer is 40785, but I think we should to be 0, also can be like 1983,36,0 combination, why - excluding this combo?