How did "STree.txt" come into being ?

[feiyangdezhu]

Under the Stanford Sentiment TreeBank, directory there are several files, which is explained clearly in the README.txt file. And i've my own dataset and i am thinking to train my own dataset using the Stanford Sentiment (RNTN). But i am wondering how do i generate the "STree.txt" file from my dataset. The format of data in "STree.txt" is in the form of:

40|39|38|37|36|34|33|32|32|31|30|30|29|28|26|25|24|23|22|22|27|23|24|25|26|27|28|29|41|31|35|33|34|35|36|37|38|39|40|41|0