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

input = raw_input()
date = []
date = input.split()
l = int(date[0])
r = int(date[1])

zero = 0
um = 0
dois = 0
tres = 0
quatro = 0
cinco = 0
seis = 0
sete = 0
oito = 0
nove = 0

for i in range(l, r+1):
	for k in str(i):	
		if "0" in k: 
			zero = zero + 1
		if "1" in k: 
			um = um + 1
		if "2" in k: 
			dois = dois + 1
		if "3" in k: 
			tres = tres + 1	
		if "4" in k: 
			quatro = quatro + 1
		if "5" in k: 
			cinco = cinco + 1
		if "6" in k: 
			seis = seis + 1
		if "7" in k: 
			sete = sete + 1
		if "8" in k: 
			oito = oito + 1
		if "9" in k: 
			nove = zero + 1

if zero>=um and zero>= dois and zero>= tres and zero>= quatro and zero>= cinco and zero>= seis and zero>= sete and zero>= oito and zero>= nove:
	print("0")
elif um>=zero and um>= dois and um>= tres and um>= quatro and um>= cinco and um>= seis and um>= sete and um>= oito and um>= nove:
	print("1")
elif dois>=zero and dois>= um and dois>= tres and dois>= quatro and dois>= cinco and dois>= seis and dois>= sete and dois>= oito and dois>= nove:
	print("2")
elif tres>=zero and tres>= um and tres>= dois and tres>= quatro and tres>= cinco and tres>= seis and tres>= sete and tres>= oito and tres>= nove:
	print("3")
elif quatro>=zero and quatro>= um and quatro>= dois and quatro>= tres and quatro>= cinco and quatro>= seis and quatro>= sete and quatro>= oito and quatro>= nove:
	print("4")
elif cinco>=zero and cinco>= um and cinco>= dois and cinco>= tres and cinco>= quatro and cinco>= seis and cinco>= sete and cinco>= oito and cinco>= nove:
	print("5")
elif seis>=zero and seis>= um and seis>= dois and seis>=tres and seis>= quatro and seis>= cinco and seis>= sete and seis>= oito and seis>= nove:
	print("6")
elif sete>=zero and sete>= um and sete>= dois and sete>=tres and sete>= quatro and sete>= cinco and sete>= seis and sete>= oito and sete>= nove:
	print("7")
elif oito>=zero and oito>= um and oito>= dois and oito>= tres and oito>= quatro and oito>= cinco and oito>= seis and oito>= sete and oito>= nove:
	print("8")
elif nove>=zero and nove>= um and nove>= dois and nove>= tres and nove>= quatro and nove>= cinco and nove>= seis and nove>= sete and nove>= oito:
	print("9")