252662256 252662260
 141650963 141650963
 4 12
 1002523 1002523
 93 95
 331900277 331900277
 56 92
 10 100
 3 1000000000
 13 13
 2 879190747
 999900001 1000000000
 820844234 892579936
 419873015 419873018
 568814539 568814539
 999999937 999999937
 519002744 519002744
 80270976 80270977
 5 10
 3 6
 392602363 392602367
 6 12
 634097178 634097179
 6 15
 3 10
 305693653 305693653
 2 3
 1200007 1200007
 5 100
 10000019 10000019
 720270740 720270743
 94 95
 908580370 968054552
 760632746 850720703
 900000011 900000011
 37622224 162971117
 5 5
 76 134
 3 12
 39 91
 999992977 999992977
 17 17
 29 29
 770439256 770439256
 347877978 913527175
 3 8
 5 15
 349533413 349533413
 100000007 100000007
 104729 104729
 900000000 1000000000
 479001599 479001599
 999727999 999727999
 1717 1717
 15 27
 100003 100003
 51 52
 17 35
 1000003 1000003
 6 8
 11 11
 741254764 741254768
 2 2
 30 37
 2 1000000000
 4 8
 620769961 988145114
 951594860 953554446
 450868287 450868290
 575062045 575062049
 28829775 28829776
 999999797 999999797
 990000023 990000023
 871232720 871232722
 242 244
 273072892 273072894
 2 999999999
 7 7
 38 98
 39916801 39916801
 998244353 998244353
 3 111111
 3 3
 982451653 982451653
 3 18
 47 52
 999999103 999999103
 999999929 999999929
 3 99
 715827883 715827883
 12 18
 999999733 999999733

2
 141650963
 2
 1002523
 2
 331900277
 2
 2
 2
 13
 2
 2
 2
 2
 568814539
 999999937
 519002744
 2
 2
 2
 2
 2
 2
 2
 2
 305693653
 2
 1200007
 2
 10000019
 2
 2
 2
 2
 900000011
 2
 5
 2
 2
 2
 999992977
 17
 29
 770439256
 2
 2
 2
 349533413
 100000007
 104729
 2
 479001599
 999727999
 1717
 2
 100003
 2
 2
 1000003
 2
 11
 2
 2
 2
 2
 2
 2
 2
 2
 2
 2
 999999797
 990000023
 2
 2
 2
 2
 7
 2
 39916801
 998244353
 2
 3
 982451653
 2
 2
 999999103
 999999929
 2
 715827883
 2
 999999733

from sys import stdout, stdin, setrecursionlimit
from io import BytesIO, IOBase
from collections import *
from itertools import *
# from random import * 
from bisect import *
from string import *
from queue import *
from heapq import *
from math import *
from re import *
from os import *

####################################---fast-input-output----#########################################


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = read(self._fd, max(fstat(self._fd).st_size, 8192))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = read(self._fd, max(fstat(self._fd).st_size, 8192))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


stdin, stdout = IOWrapper(stdin), IOWrapper(stdout)
graph, mod, szzz =  {}, 10**9 + 7, lambda: sorted(zzz())
def getStr(): return input()
def getInt(): return int(input())
def listStr(): return list(input())
def getStrs(): return input().split()
def isInt(s): return '0' <= s[0] <= '9'
def input(): return stdin.readline().strip()
def zzz(): return [int(i) for i in input().split()]
def output(answer, end='\n'): stdout.write(str(answer) + end)
def lcd(xnum1, xnum2): return (xnum1 * xnum2 // gcd(xnum1, xnum2))




dx = [-1, 1, 0, 0, 1, -1, 1, -1]
dy = [0, 0, 1, -1, 1, -1, -1, 1]
daysInMounth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]


#################################################---Some Rule For Me To Follow---#################################
"""
    --instants of Reading problem continuously try to understand them.

    --If you Know some-one , Then you probably don't know him !

    --Try & again try

"""
##################################################---START-CODING---###############################################

a,b=zzz()
rem = b-a

two=(rem//2)+b%2==0 + a%2==0
three = rem//3 + b%3==0 + a%3==0

print(2 if max(three,two)==two else 3)
