Rain falls on a pen-drawn street. You deliver letters. The umbrella is your only roof.The rain comes at an angle — when the wind shifts, tilt your umbrella. 伞的朝向（↑↓ 或 拖动）决定哪一侧挡雨；迎风走淋得快，屋檐下能晾干。 Wet 100% 这封信就糊了。送出 5，换一条更长的街。