Problem:
Score : 100 points

Problem Statement

You are given two positive integers a and b.
Let x be the average of a and b.
Print x rounded up to the nearest integer.

Constraints

a and b are integers.

1 \leq a, b \leq 100

Input

Input is given from Standard Input in the following format:

a b

Output

Print x rounded up to the nearest integer.

Sample Input 1

1 3

Sample Output 1

2

The average of 1 and 3 is 2.0, and it will be rounded up to the nearest integer, 2.

Sample Input 2

7 4

Sample Output 2

6

The average of 7 and 4 is 5.5, and it will be rounded up to the nearest integer, 6.

Sample Input 3

5 5

Sample Output 3

5

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

<?php

class Scanner
{
    private $arr = [];
    private $count = 0;
    private $pointer = 0;

    public function next()
    {
        if ($this->pointer >= $this->count) {
            $str = trim(fgets(STDIN));
            $this->arr = explode(" ", $str);
            $this->count = count($this->arr);
            $this->pointer = 0;
        }
        $result = $this->arr[$this->pointer];
        $this->pointer++;
        return $result;
    }

    public function hasNext()
    {
        return $this->pointer < $this->count;
    }

    public function nextInt()
    {
        return (int)$this->next();
    }

    public function nextDouble()
    {
        return (double)$this->next();
    }
}

class out
{
    public static function printIn($str = "")
    {
        echo $str . PHP_EOL;
    }
}

$sc = new Scanner;

$a = $sc->nextInt();
$b = $sc->nextInt();

echo ceil(($a + $b) / 2);