import std.stdio, std.conv, std.string, std.range, std.algorithm, std.range;

void main()
{
  auto N = readln.split[0].to!int;
  iota(1, N + 1).map!"a.to!string"
    .map!"a.length"
    .count!"(a & 1) == 1"
    .writeln;
}
