#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll n, len;
int main(){
    cin>>n;
    if(n < 10) return printf("%d\n", n+1);
    ll tmp = n;
    while(tmp) len++, tmp /= 10;
    ll ans = (len-1) * 10;
    tmp = n;
    while(tmp >= 10) tmp /= 10;
    ans += tmp-1;
    ll tmp1 = 0;
    for(int i=1;i<=len;i++){
        tmp1 = tmp + tmp1 * 10;
    }
    if(tmp1 <= n) ans++;
    cout<<ans<<endl;
    return 0;
}