#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define fi first
#define se second
#define vi vector<int>
#define vl vector<ll>
#define vb vector<bool>
#define vs vector<string>
#define pii pair<int, int>
#define pib pair<int, bool>
#define pdd pair<double, double>
#define mii map<int, int>
#define mib map<int, bool>
#define mil map<int, ll>
#define mli map<ll, int>
#define si set<int>
#define vvi vector<vi>
#define vvl vector<vl>
#define vvb vector<vb>
#define vpi vector<pii>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sub(x, l, r) (x).begin() + l, (x).begin() + r
#define rsub(x, l, r) (x).rbegin() + l, (x).rbegin() + r
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; i++)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; i--)

#define yes cout << "YES\n";
#define no cout << "NO\n";
#define yn yes else no
#define ny no else yes

#define int ll

#ifdef VanLam
#include <debug.h>
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 1205
#endif

const int INF = 1e9 + 7;
const int MOD = 1e9 + 7;
const int maxN = 1e6 + 5;

int calc(int n, int digit)
{
    int tmp = 0;
    int res = 0;
    while (n >= tmp * 10 + digit)
    {
        res++;
        tmp = tmp * 10 + digit;
    }

    return res;
}

int LOG10(int n)
{
    int res = 0;
    while (n)
    {
        res++;
        n /= 10;
    }
    return res;
}

void solve()
{
    int n;
    cin >> n;
    int res = LOG10(n) - 1;
    if (!res)
        res = 1;
    debug(res);
    FOR(digit, 1, 9)
    {
        res += calc(n, digit);
        debug(digit, res);
    }

    cout << res;
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if (fopen("input.txt", "r"))
    {
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    }

    int t = 1;
    // cin >> t;
    int testcase = 1;
    while (t--)
    {
        cerr << "------ CASE: " << testcase++ << " ------\n";
        solve();
        cerr << "-------- END --------\n";
    }
    return 0;
}