So episode 20 was a false alarm, it's not the ending of Autumn's Concerto. This week is the real last week of waiting. The last episode is episode 21.
21 is a great number and it also represents the happiness at this last stop! Why?
Because 21=2+1=3. Still don't see it?
21 = (Mu Cheng + Guang Xi) + Xiao Le = Happy Family of 3