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 C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var dump = Console.ReadLine();
            var A = Console.ReadLine().Split(' ').Select(x => Convert.ToInt32(x)).OrderBy(x => x).ToArray();
            var dec = new Dictionary<int, int>();
            var sum = 0;

            foreach(var a in A)
            {
                dec[a]++;
            }

            foreach(var elem in dec)
            {
                var key = elem.Key;
                var value = elem.Value;
                if(key == value)
                {

                }
                else if(key > value)
                {
                    sum += value;
                }
                else
                {
                    sum += (value - key);
                }
            }
            Console.WriteLine(sum);

            
        }
    }
}