package main

import . "fmt"

func main() {
	var n uint64
	Scan(&n)
	m:=map[uint64]bool{}
	for i:=uint64(1);;i*=10 {
			for e:=i*0;e<i*10;e+=i {
				x:=n/i*10*i+e+n%i
				m[x]=true
			}
			if i>n {
				break
			}
	}
	delete(m,n)
	Println(len(m))
}