using System;

namespace RacineCarree
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Console.Write("Saisir x : ");
			double x = double.Parse(Console.ReadLine());
			double min = 0;
			double max = x+1;
			double eps = 1e-12;
			double mid;
			do
			{
				mid = (min + max)/2;
				if(mid*mid > x)
					max = mid;
				else
					min = mid;
			}
			while(max - min > eps);
			Console.WriteLine("sqrt(" + x + ") = " + mid);
		}
	}
}