南航北骑

Explanation: The phrase "Let Huainanzi vulgar training": "barbarian easy horse, the more easy boat people." After due to the "Southern North ride" to describe the boat riding, running north and south. 　　Source: Phrase "Let Huainanzi vulgar training" barbarian easy horse, the more people easy boat. " 　　Examples: Wan and West, should Bingong tour two are, ~, Ru Ren Yan ground with a reason that benefits weary. ★ Ming Wu Cheng-en "in sub-Ru-Shou Hu, Zhi-sequence were six"