import sys
from functools import reduce
def a():
    p = [[int(t) for t in r.split(' ')] for r in sys.stdin.read().split('\n') if r != '']
    A, P = p[0]
    print(int((A*3+P)/2)
a()
import sys
def a():
    p = [[int(t) for t in r.split(' ')] for r in sys.stdin.read().split('\n') if r != '']
    A, P = p[0]
    print(int((A*3+P)/2)
a()
