noname43

#include<bits/stdc++.h>
#include<conio.h>
#include<time.h>


using namespace std;


#define f first
#define s second
#define ll long long
#define ld long double
#define MOD 1000000007
#define PI (2*acos(0))
#define pll pair<ll, ll>
#define pii pair<int, int>
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define vvll vector<vll>
#define pb push_back


#define FOR(i, a, b) for(ll i = (a); i <= (b); i++)
#define FORn(i, n) for(ll i = 1; i <= (n); i++)
#define FORx(i, a, b, n) for(ll i = (a); i <= (b); i += (x))
#define FORa(i, b) for(; i <= (b); i++)
#define FORax(i, b, x) for(; i <= (b); i += (x))
#define FORR(i, a, b) for(ll i = (a); i >= (b); i--)
#define FORRn(i, n) for(ll i = (n); i >= 1; i--)
#define FORRx(i, a, b, n) for(ll i = (a); i >= (b); i -= (x))
#define FORRa(i, b) for(; i >= (b); i--)
#define FORRax(i, b, x) for(; i >= (b); i -= (x))


#define all(x) (x).begin(), (x).end()
#define sz(x) (x).size()
#define sqr(x) 1ll*(x)*(x)


template <typename T>
inline void Read(T& x) {
    bool Neg = false;
    char c;
    for (c = getchar(); c < '0' || c > '9'; c = getchar())
        if (c == '-') Neg = !Neg;
    x = c - '0';
    for (c = getchar(); c >= '0' && c <= '9'; c = getchar())
        x = x * 10 + c - '0';
    if (Neg) x = -x;
}
template <typename T>
inline void Write(T x) {
    if (x < 0)
    {
        putchar('-'); x = -x;
    }
    T p = 1;
    for (T temp = x / 10; temp > 0; temp /= 10) p *= 10;
    for (; p > 0; x %= p, p /= 10) putchar(x / p + '0');
}







    /* ----------------- useful func ----------------- */
    template <typename T> inline
    void SieveOfEratosthenes(T n){
        vector<T> prime(n + 1, true);
        prime[0] = prime[1] = false;
        for (int p = 2; p*p <= n; p++)
            if (prime[p] == true)
                for (int i = p*p; i <= n; i += p)
                    prime[i] = false;
        for (int p = 2; p <= n; p++)
            if (prime[p]){
                Write(p); putchar('\n');
            }
    }
    vvll operator * (vvll a, vvll b){
        ll M = sz(a), N = sz(b), P = sz(b[0]);
        vvll res(M, vll(N, 0));
        FOR(i, 0, M - 1)
            FOR(j, 0, P - 1)
                FOR(k, 0, N-1)
                    res[i][j] += a[i][k]*b[k][j];
        return res;
    }
    template <typename T> inline
    T power(T a, ll n){
        if(n == 1) return a;
        T t = power(a, n/2);
        return (n & 1) ? t*t*a : t*t;
    }






/* ----------------- ~~~~~~~~~~~ ----------------- */
        /* ----------------- ~~~~~~~ ----------------- */
    ll n, t = 1, r = 10, sum = 0;






/* ----------------- ~~~~~~~ ----------------- */

int main(){
    //freopen("INPUT.inp", "r", stdin);
    //freopen("OUTPUT.out", "w", stdout);
    //ios_base::sync_with_stdio(0); cin.tie(0);

        /* ----------------- main func ----------------- */
    Read(n);
    while(r-1 < n){
        sum += t*r*9/10;
        r*= 10;
        t++;
    }
    Write(sum + (n - r/10 + 1)*t);








/* ----------------- ~~~~~~~~~ ----------------- */
}