#!/usr/bin/env PyPy3

from collections import Counter, defaultdict, deque
import itertools
import re
import math
from functools import reduce
import operator
import bisect
import heapq
import functools
mod=10**9+7

import sys
input=sys.stdin.readline

x,y=map(int,input().split())
if abs(x-y) == 4:
    print((max(x,y)+4) % 12)
else:
    print((x+y) // 2)