import std.algorithm, std.array, std.container, std.range, std.bitmanip;
import std.numeric, std.math, std.bigint, std.random, core.bitop;
import std.string, std.regex, std.conv, std.stdio, std.typecons;

void main()
{
  auto n = readln.chomp.to!real;

  auto pma = n / 10000 * 0.99;
  auto pca = (1 - n / 10000) * 0.01;
  auto pa = pma + pca;
  writeln((1 - n / 10000) / pa);
}