using System;
using System.IO;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Numerics;
using System.Threading.Tasks;
using System.Text.RegularExpressions;
using static System.Math;
using Debug = System.Diagnostics.Debug;
using LayoutKind = System.Runtime.InteropServices.LayoutKind;

static class P
{
    static void Main()
    {
        Console.WriteLine(Round(Sqrt(long.Parse(Console.ReadLine()) / PI)));
    }
}