#include <bits/stdc++.h>
int main() {
  long long int n, i, p = 1, k, x = 0, s = 0;
  scanf("%lld", &n);
  k = n;
  while (k != 0) {
    k = k / 10;
    x++;
  }
  for (i = 1; i <= x - 1; i++) {
    p = p * 10;
  }
  while (x != 0) {
    s = s + (n - p + 1) * x;
    n = p - 1;
    p = p / 10;
    x--;
  }
  printf("%lld", s);
}
