赶快

赶快	gǎn kuài	quickly; at once
赶	gǎn	to overtake; to catch up with / to hurry; to rush / to try to catch (the bus etc) / to drive (cattle etc) forward; to drive (sb) away / to avail oneself of (an opportunity) / until; by (a certain time)
快	kuài	rapid / quick / speed / rate / soon / almost / to make haste / clever / sharp (of knives or wits) / forthright / plainspoken / gratified / pleased / pleasant