def LI():
  return [int(s) for s in input().split()]

A,P = LI()

print((A*3 + P) // 2) def LI():
  return [int(s) for s in input().split()] LI int(s) for s in input().split() for s in input().split() s input().split() ().split () input split for s in input().split() int(s) int s return [int(s) for s in input().split()] [int(s) for s in input().split()] A,P = LI() A LI() LI P print((A*3 + P) // 2) print (A*3 + P) // 2 A*3 + P A*3 A 3 P 2 P = LI() LI() P A,P = LI() LI() A def LI():
  return [int(s) for s in input().split()] def LI():
  return [int(s) for s in input().split()] LI
def LI():
  return [int(s) for s in input().split()]

A,P = LI()

print((A*3 + P) // 2)