New tickets were introduced in Yekaterinburg trams. Their numbers don't have leading zeroes; they just go one after another, starting from number one. Some passengers were embarrassed at hearing this news: now they didn't know how to determine whether a ticket was lucky. New versions of the luckiness criterion were discussed in trams, at tram stops, and, of course, at the tram forum on the Web. According to one of the versions, a ticket was considered lucky if no two opposite digits of its number coincided; i.e., d_i ≠ d_n+1−i for i ≠ n + 1 − i, where d₁d₂…d_n was the number of the ticket.

One of the addicts of the tram forum was a programmer, and he decided to calculate the amount of lucky tickets in a conductor's roll if the number of the first ticket in the roll was a, and the number of the last ticket was b; the tickets in the roll are numbered consecutively.

The input line contains the integers a and b separated by a space (1 ≤ a ≤ b ≤ 10¹⁸).

Output the amount of lucky tickets in the roll.