Distance between Two Points

Version: Phuoc Hung OJ Extended

Problem Statement

Given two points $A(x_1,y_1)$ and $B(x_2,y_2)$ in the plane, compute their Euclidean distance $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$. Print exactly 6 decimal places.

Input

The only line contains four real numbers $x_1$, $y_1$, $x_2$, $y_2$ describing the points.

Output

Print the distance between the two points with exactly 6 decimal places.

Subtasks

• Subtask 1 (100 points): $|x_i|,|y_i|\le10^9$.

Examples

Example 1

Input

0 0 3 4

Output

5.000000

Explanation. Substituting 0, 0, 3, 4 into sqrt((x₂-x₁)² + (y₂-y₁)²) gives approximately 5. The required output formatting produces 5.000000.

Example 2

Input

1 1 1 1

Output

0.000000

Explanation. Substituting 1, 1, 1, 1 into sqrt((x₂-x₁)² + (y₂-y₁)²) gives approximately 0. The required output formatting produces 0.000000.

Example 3

Input

-1 -1 2 3

Output

5.000000

Explanation. Substituting -1, -1, 2, 3 into sqrt((x₂-x₁)² + (y₂-y₁)²) gives approximately 5. The required output formatting produces 5.000000.