import java.util.*;

// given 2 points x1,y1, and x2,y2, compute the distance between them using the Euclidean distance formula:
//    distance = square root [(x1 - x2)^2 + (y1 - y2)^2]

public class Prog2_15
{
	public static void main(String[] args)
	{
		Scanner in = new Scanner(System.in);			// keyboard input
		int x1, y1, x2, y2;								// the 4 values that make up the two points
		System.out.print("enter the first x-coordinate: ");
		x1 = in.nextInt();
		System.out.print("enter the first y-coordinate: ");
		y1 = in.nextInt();		
		System.out.print("enter the second x-coordinate: ");
		x2 = in.nextInt();
		System.out.print("enter the second y-coordinate: ");
		y2 = in.nextInt();					
		double distance = Math.sqrt(Math.pow(x1-x2,2)+Math.pow(y1-y2,2));
		System.out.print("The distance between " + x1 + "," + y1 + " and " + x2 + "," + y2 + " is ");
		System.out.printf("%6.2f", distance);
	}
}