Polycarpus loves lucky numbers. Everybody knows that lucky numbers are positive integers, whose decimal representation (without leading zeroes) contain only the lucky digits $*x*$ and $*y*$. For example, if $*x* = 4$, and $*y* = 7$, then numbers 47, 744, 4 are lucky.

Let's call a positive integer $*a*$ undoubtedly lucky, if there are such digits $*x*$ and $*y*$ $(0 ≤ *x*, *y* ≤ 9)$, that the decimal representation of number $*a*$ (without leading zeroes) contains only digits $*x*$ and $*y*$.

Polycarpus has integer $*n*$. He wants to know how many positive integers that do not exceed $*n*$, are undoubtedly lucky. Help him, count this number.

Input

The first line contains a single integer $*n*$ $(1 ≤ *n* ≤ 10^{9})$ — Polycarpus's number.

Output

Print a single integer that says, how many positive integers that do not exceed $*n*$ are undoubtedly lucky.

Note

In the first test sample all numbers that do not exceed $10$ are undoubtedly lucky.

In the second sample numbers 102, 103, 104, 105, 106, 107, 108, 109, 120, 123 are not undoubtedly lucky.