#!/usr/bin/env python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from functools import lru_cache


@lru_cache(None)
def count12(L, R):
    if L == R:
        return str(L).count('12')
    if L > R:
        return 0
    x = (L - 12 + 99) // 100
    y = (R - 12) // 100
    ret = y - x + 1
    for i in range(10):
        x = (L - i + 9) // 10
        y = (R - i) // 10
        ret += count12(x, y)
    return ret


def count12_naive(L, R):
    return sum(str(n).count('12') for n in range(L, R + 1))


def count_2xx1(L, R):
    def count_2xx(L, R):
        ret = 0
        for keta in range(0, 20):
            low = 2 * (10 ** keta)
            high = 3 * (10 ** keta) - 1
            if low < L:
                low = L
            if high > R:
                high = R
            if low <= high:
                ret += high - low + 1
        return ret
    x = (L - 1 + 9) // 10
    y = (R - 1) // 10
    return count_2xx(x, y)


def count_2xx1_naive(L, R):
    return sum(str(n)[0] == '2' and n % 10 == 1 for n in range(L, R + 1))


def solve(A, B):
    ret = count12(A, B)
    if A < B:
        ret += count_2xx1(A, B - 1)
    if A <= 1 and 2 <= B:
        ret += 1
    return ret


A, B = map(int, read().split())
print(solve(A, B))