import java.util.Scanner;
public class CoordinateGeometry {
public static void main(String [] args) {
Scanner scnr = new Scanner(System.in);
double x1;
double y1;
double x2;
double y2;
double pointsDistance;
double xDist;
double yDist;
pointsDistance = 0.0;
xDist = 0.0;
yDist = 0.0;
x1 = scnr.nextDouble();
y1 = scnr.nextDouble();
x2 = scnr.nextDouble();
y2 = scnr.nextDouble();
poinsDistance = Math.sqrt(Math.pow(x2 - x1, 2) + (Math.pow(y2 - y1, 2));
System.out.println(pointsDistance);
}
}
public class Solution {
public double MyPow(double x, int n) {
}
}
class Solution {
public:
double myPow(double x, int n) {
}
};
class Solution {
public double myPow(double x, int n) {
}
}
double myPow(double x, int n){
}
/**
* @param {number} x
* @param {number} n
* @return {number}
*/
var myPow = function(x, n) {
};
# @param {Float} x
# @param {Integer} n
# @return {Float}
def my_pow(x, n)
end
class Solution {
func myPow(_ x: Double, _ n: Int) -> Double {
}
}
class Solution {
/**
* @param Float $x
* @param Integer $n
* @return Float
*/
function myPow($x, $n) {
}
}
function myPow(x: number, n: number): number {
};