a = [1,31,29,31,30,31,30,31,31,30,31,30,31] n = int(input()) if n==1 or n==2 or n==3 or n==4 or n==5 or n==6 or n==7 or n==8 or n==9 or n==10 or n==11 or n==12 or : print("a"[n]) else: print("Invalid.")