Another legend about the Jiayuguan Pass tells of a workman named Yi Kaizhan in the Ming Dynasty (1368BC-1644BC) who was proficient in arithmetic. He calculated that it would need 99,999 bricks to build the Jiayuguan Pass. The supervisor did not believe him and said if they miscalculated by even one brick, then all the workmen would be punished to do hard work for three years. After the completion of the project, one brick was left behind the Xiwong city gate. The supervisor was happy at the sight of the brick and ready to punish them. However Yi Kaizhan said with deliberation that the brick was put there by a supernatural being to fix the wall. A tiny move would cause the collapse of the wall. Therefore the brick was kept there and never moved. It can still be found there today on the tower of the Jiayuguan Pass.