0 → push start -- （汽车因难发动而）推车起动（同 push start）
1 → push-start -- （汽车因难发动而）推车起动（同 push-start）
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
再长的路，一步步也能走完，再短的路，不迈开双脚也无法到达。
