using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace YukiCoder2
{
    class Program
    {
        static void Main(string[] args)
        {
            var line = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            var n = line[0];
            var max = 1;
            for (int i = 1; i < n / 2 + 1; i++)
            {
                if (n%i == 0)
                {
                    max = i;
                }
            }
            Console.WriteLine(max);
        }
    }
}