inp=input()
list=inp.split()
a, p=list[0], list[1]
print(int(((int(a)*3)+int(p))/2)) inp=input() inp input() input list=inp.split() list inp.split() inp.split inp split a, p=list[0], list[1] a list[0] list 0 p list[1] list 1 print(int(((int(a)*3)+int(p))/2)) print int(((int(a)*3)+int(p))/2) int ((int(a)*3)+int(p))/2 (int(a)*3)+int(p) int(a)*3 int(a) int a 3 int(p) int p 2 inp=input() input() inp a, p=list[0], list[1] list[0] a list=inp.split() inp.split() list p=list[0], list[1] list[1] p
inp=input()
list=inp.split()
a, p=list[0], list[1]
print(int(((int(a)*3)+int(p))/2))