#include <bits/stdc++.h>
const double PI =
    3.141592653589793238462643383279502884197169399375105820974944;
using namespace std;
long long arr[] = {0,     9,      90,      900,      9000,
                   90000, 900000, 9000000, 90000000, 900000000};
long long arr1[] = {0,     9,      99,      999,      9999,
                    99999, 999999, 9999999, 99999999, 999999999};
void solve() {
  long long n;
  cin >> n;
  int digits = 0;
  long long temp = n;
  while (temp != 0) {
    ++digits;
    temp = temp / 10;
  }
  long long ans = 0;
  for (long long i = 0; i < digits; ++i) {
    ans += arr[i] * (i);
  }
  ans += (n - arr1[digits - 1]) * (digits);
  cout << ans << "\n";
}
int main() {
  bool testing = false;
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  if (testing) {
    freopen("test.txt", "rt", stdin);
    int start = clock();
    solve();
    int end = clock();
    cout << "time: " << (end - start) / (double)(CLOCKS_PER_SEC)*1000
         << " milliseconds\n";
  } else {
    solve();
  }
}
