/* -*- coding: utf-8 -*-
 *
 * 2607.cc:  No.2607 Add One Digit - yukicoder
 */

#include<cstdio>
#include<set>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_L = 11;

/* typedef */

typedef long long ll;
typedef set<int> sl;

/* global variables */

int ds[MAX_L];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  int l = 0;
  while (n > 0) ds[l++] = n % 10, n /= 10;

  sl as;
  for (int i = l; i >= 0; i--) {
    for (int d = (i == l) ? 1 : 0; d <= 9; d++) {
      ds[i] = d;
      ll a = 0;
      for (int j = l; j >= 0; j--) a = a * 10 + ds[j];
      as.insert(a);
    }
    if (i > 0) ds[i] = ds[i - 1];
  }

  printf("%d\n", (int)as.size());

  return 0;
}