Let's denote a function f(x) in such a way: we add 1 to x, then, while there is at least one trailing zero in the resulting number, we remove that zero. For example, 

  * f(599) = 6: 599 + 1 = 600 → 60 → 6; 
  * f(7) = 8: 7 + 1 = 8; 
  * f(9) = 1: 9 + 1 = 10 → 1; 
  * f(10099) = 101: 10099 + 1 = 10100 → 1010 → 101. 



We say that some number y is reachable from x if we can apply function f to x some (possibly zero) times so that we get y as a result. For example, 102 is reachable from 10098 because f(f(f(10098))) = f(f(10099)) = f(101) = 102; and any number is reachable from itself.

You are given a number n; your task is to count how many different numbers are reachable from n.

Input

The first line contains one integer n (1 ≤ n ≤ 10^9).

Output

Print one integer: the number of different numbers that are reachable from n.

Examples

Input


1098


Output


20


Input


10


Output


19

Note

The numbers that are reachable from 1098 are:

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1098, 1099.
#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __s(Arg1&& arg1) {
  cin >> arg1;
}
template <typename Arg1, typename... Args>
void __s(Arg1&& arg1, Args&&... args) {
  cin >> arg1;
  __s(args...);
}
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
std::vector<std::string> tokenize(const std::string& s,
                                  const std::string& delims) {
  std::vector<std::string> tokens;
  size_t offset = 0;
  while (true) {
    size_t nonDelim = s.find_first_not_of(delims, offset);
    if (nonDelim == std::string::npos) {
      break;
    }
    size_t delim = s.find_first_of(delims, nonDelim);
    if (delim == std::string::npos) {
      tokens.push_back(s.substr(nonDelim));
      break;
    }
    tokens.push_back(s.substr(nonDelim, delim - nonDelim));
    offset = delim;
  }
  return tokens;
}
int main() {
  long long n;
  __s(n);
  map<long long, bool> exists;
  int ans = 0;
  exists[n] = 1;
  ans = 1;
  while (n != 1) {
    n++;
    while (n % 10 == 0) n /= 10;
    if (!exists[n]) {
      exists[n] = 1;
      ans++;
    }
    __f("n", n);
  }
  for (int i = 1; i < 10; i++) {
    if (!exists[i]) {
      exists[i] = 1;
      ans++;
    }
  }
  cout << ans << endl;
  return 0;
}
