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

namespace _04.DistanceBetweenPoints
{
    class DistanceBetweenPoints
    {
        static void Main(string[] args)
        {
            
            Point p1 = ReadPoint();
            Point p2 = ReadPoint();

            double distance = CalcDistance(p1, p2);

            Console.WriteLine("Distance: {0:f3}", distance);

        }
        static Point ReadPoint()
        {
            double[] pointInfo = Console.ReadLine().Split().Select(double.Parse).ToArray();
            Point point = new Point();
            point.X = pointInfo[0];
            point.Y = pointInfo[1];
            return point;
        }
        static double CalcDistance(Point p1, Point p2)
        {
            double deltaX = p2.X - p1.X;
            double deltaY = p2.Y - p1.Y;
            return Math.Sqrt(deltaX * deltaX + deltaY * deltaY);
        }

    }
}
