A Buddhist scripture, teach us a method to be awareness by black or white stones

Excerpts from Buddhist scriptures《The Sutra of the Wise and Foolish》: Used to have a great sage: Upagupta, his master teach him a method to to tame the Mind, and he was determined to eliminate all of his shortcomings. During the day, whenever proceed evil thoughts, he put a black stone, rise good thoughts to put a white stones. One day down, he counted the number of black stone, how many white stones. At first, all black stones; but too soon, due to continued vigilance, the quantity of black stones and white stones are the same. Finally, when he was completely tame volts Mind, only white stones.

Many gurus also been mentioned on this story. We hope the most commonly used devices in the modern, could have an APP provide one from ancient teachings, thus we do it. I hope everyone has the opportunity to be able to facilitate the use of this ancient method, constantly remind yourself always in a state of awareness.