Average of Three Numbers

Version: Phuoc Hung OJ Extended

Problem Statement

Given three real numbers $a$, $b$ and $c$, compute their arithmetic mean $M=\dfrac{a+b+c}{3}$. Print it in fixed-point notation with exactly 3 decimal places.

Input

One line contains real numbers a,b,c.

Output

Print the arithmetic mean with exactly 3 decimal places.

Subtasks

• Subtask 1 (100 points): $|a|,|b|,|c|\le10^{12}$.

Examples

Example 1

Input

1 2 3

Output

2.000

Explanation. Substituting 1, 2, 3 into (a + b + c) / 3 gives approximately 2. The required output formatting produces 2.000.

Example 2

Input

1.1 2.2 3.3

Output

2.200

Explanation. Substituting 1.1, 2.2, 3.3 into (a + b + c) / 3 gives approximately 2.2. The required output formatting produces 2.200.

Example 3

Input

-1 0 1

Output

0.000

Explanation. Substituting -1, 0, 1 into (a + b + c) / 3 gives approximately 0. The required output formatting produces 0.000.