Kinetic Energy

Version: Phuoc Hung OJ Extended

Problem Statement

An object has mass $m$ and velocity $v$. Its kinetic energy is $E=\dfrac12mv^2$. Compute $E$ and print exactly 3 decimal places. Since velocity is squared, a negative velocity still yields nonnegative kinetic energy.

Input

The only line contains real mass $m$ and velocity $v$.

Output

Print kinetic energy $E$ with exactly 3 decimal places.

Subtasks

• Subtask 1 (100 points): $m\ge0$ and $v$ is a finite real number.

Examples

Example 1

Input

2 3

Output

9.000

Explanation. Substituting 2, 3 into (1/2) × m × v² gives approximately 9. The required output formatting produces 9.000.

Example 2

Input

1.5 10

Output

75.000

Explanation. Substituting 1.5, 10 into (1/2) × m × v² gives approximately 75. The required output formatting produces 75.000.

Example 3

Input

0 100

Output

0.000

Explanation. Substituting 0, 100 into (1/2) × m × v² gives approximately 0. The required output formatting produces 0.000.