import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
write=sys.stdout.write

A,B=map(int,readline().split())
B+=1
def solve(x):
    xx=x
    X=list(map(int,list(str(x))))
    dp=[0]*2
    dp_cnt=[0]*2
    for i in range(1,X[0]):
        if i==1:
            dp_cnt[1]+=1
        else:
            dp_cnt[0]+=1
    cnt=0
    if X[0]==1:
        cur=1
    else:
        cur=0
    for x in X[1:]:
        prev=dp
        prev_cnt=dp_cnt
        dp=[0]*2
        dp_cnt=[0]*2
        for i in range(10):
            if i==1:
                dp[1]+=prev[0]+prev[1]
                dp_cnt[1]+=prev_cnt[0]+prev_cnt[1]
            elif i==2:
                dp[0]+=prev[0]+prev[1]+prev_cnt[1]
                dp_cnt[0]+=prev_cnt[0]+prev_cnt[1]
            else:
                dp[0]+=prev[0]+prev[1]
                dp_cnt[0]+=prev_cnt[0]+prev_cnt[1]
        for i in range(1,10):
            if i==1:
                dp_cnt[1]+=1
            else:
                dp_cnt[0]+=1
        for i in range(x):
            if i==1:
                dp[1]+=cnt
                dp_cnt[1]+=1
            elif i==2:
                dp[0]+=cnt
                if cur:
                    dp[0]+=1
                dp_cnt[0]+=1
            else:
                dp[0]+=cnt
                dp_cnt[0]+=1
        if x==1:
            cur=1
        elif x==2 and cur:
            cnt+=1
            cur=0
        else:
            cur=0
    ans=0
    x=xx
    if x>=3:
        ans+=1
        x+=7
        x//=10
        le=len(str(x))
        for i in range(le-1):
            ans+=10**i
        ans+=max(0,min(10**(le-1),x-2*10**(le-1)))
    return ans+dp[0]+dp[1]
ans=solve(B)-solve(A)
if int(str(A)[0])==2 and A%10==2:
    ans-=1
print(ans)