 Emperor Xiaowu agreed.Yuwen next sent a letter to Houmochen to rebuke him, and when Houmochen did not answer, prepared to launch an attack on Houmochen.He advanced quickly on Shuiluo, and Houmochen withdrew to Lüeyang (略陽, in modern Tianshui, Gansu), and then to Shanggui (上邽, also in modern Tianshui).