#include <bits/stdc++.h>
using namespace std;
int dcount(long long i) {
  int c = 0;
  while (i > 0) {
    i = i / 10;
    c++;
  }
  return c;
}
int main() {
  long long n, cnt = 0;
  cin >> n;
  int num = dcount(n);
  for (long long int i = 0; i < num; i++) {
    cnt += n > (pow(10, i + 1) - 1) ? (pow(10, i + 1) - pow(10, i)) * (i + 1)
                                    : (n - pow(10, i) + 1) * (i + 1);
  }
  cout << cnt;
}
