Problem H
Computer, compute!

You likely know the Euclidean distance formula – the formula to find the distance $d$ between two points, $(x_1,y_1)$ and $(x_2,y_2)$, in a plane.

The formula is $d=\sqrt{(x_2-x_1{)}^2+(y_2-y_1{)}^2}$

You will take the two integer coordinates as input and compute the distance between them.

Hint: You can use the sqrt function in the math module.

Input

Input consists of four lines. The first line consists of one integer $x_1$, the $x$-coordinate of the first point. The second line consists of one integer $y_1$, the $y$-coordinate of the first point. The third line consists of one integer $x_2$, the $x$-coordinate of the second point. The fourth line consists of one integer $y_2$, the $y$-coordinate of the second point. It is guaranteed that $-10000\le x_1,y_1,x_2,y_2\le 10000$.

Output

Output one line with one floating point number $d$, the Euclidean distance between the two points. The output number should have an absolute or relative error of at most ${10}^{-9}$.

-5
-5
-11
-13

10.000000000000000

0
0
0
0

0.000000000000000

1
1
5
4

5.000000000000000

3
4
3
4

0.000000000000000

4
-3
-5
9

15.000000000000000

7
20
12
8

13.000000000000000