Average Without Early Rounding

Version: Phuoc Hung OJ Extended

Problem Statement

Given real numbers $a$, $b$ and $c$, compute their mean $M=\dfrac{a+b+c}{3}$ using the original values and format only the final result to 2 decimal places. Do not round the inputs before summing them.

Input

The only line contains three real numbers $a$, $b$, $c$.

Output

Print arithmetic mean $M$ with exactly 2 decimal places.

Subtasks

• Subtask 1 (100 points): $|a|,|b|,|c|\le10^9$.

Examples

Example 1

Input

1.234 2.345 3.456

Output

2.35

Explanation. Substituting 1.234, 2.345, 3.456 into (a + b + c) / 3 gives approximately 2.345. The required output formatting produces 2.35.

Example 2

Input

19.995 19.995 19.995

Output

20.00

Explanation. Substituting 19.995, 19.995, 19.995 into (a + b + c) / 3 gives approximately 19.995. The required output formatting produces 20.00.

Example 3

Input

0.1 0.2 0.3

Output

0.20

Explanation. Substituting 0.1, 0.2, 0.3 into (a + b + c) / 3 gives approximately 0.2. The required output formatting produces 0.20.