Problem:
Score: 100 points

Problem Statement

There is a train going from Station A to Station B that costs X yen (the currency of Japan).

Also, there is a bus going from Station B to Station C that costs Y yen.

Joisino got a special ticket. With this ticket, she can take the bus for half the fare if she travels from Station A to Station B by train and then travels from Station B to Station C by bus.

How much does it cost to travel from Station A to Station C if she uses this ticket?

Constraints

1 \leq X,Y \leq 100

Y is an even number.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

X Y

Output

If it costs x yen to travel from Station A to Station C, print x.

Sample Input 1

81 58

Sample Output 1

110

The train fare is 81 yen.

The train fare is 58 ⁄ 2=29 yen with the 50% discount.

Thus, it costs 110 yen to travel from Station A to Station C.

Sample Input 2

4 54

Sample Output 2

31

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

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

namespace myapp
{
    class Program
    {
        class Class1
        {
            public int prefectureNumber { get; set; }
            public int year { get; set; }
            public int inputNumber { get; set; }
        }

        class Class2
        {
            public int prefectureNumber { get; set; }
            public int cityOrder { get; set; }
            public int inputNumber { get; set; }
        }

        static void Main(string[] args)
        {
            IReadOnlyList<int> lineString = Console.ReadLine().Split(' ').Select(str => int.Parse(str)).ToList();
            int prefectureCount = lineString[0];
            int cityCount = lineString[1];

            List<Class1> conditionList = new List<Class1>();
            for (int i = 0; i < cityCount; i++)
            {
                IReadOnlyList<int> conditionLine = Console.ReadLine().Split(' ').Select(str => int.Parse(str)).ToList();
                conditionList.Add(new Class1
                {
                    prefectureNumber = conditionLine[0],
                    year = conditionLine[1],
                    inputNumber = i + 1
                });
            }

            int cityOrder = 1;
            int currentPrefecture = 0;
            List<Class2> orderedConditionList2 = new List<Class2>();
            foreach (var condition in conditionList.OrderBy(condition => condition.prefectureNumber).ThenBy(condition => condition.year).ToList())
            {
                if (condition.prefectureNumber != currentPrefecture)
                {
                    cityOrder = 1;
                }
                orderedConditionList2.Add(new Class2
                {
                    prefectureNumber = condition.prefectureNumber,
                    cityOrder = cityOrder,
                    inputNumber = condition.inputNumber
                });
                currentPrefecture = condition.prefectureNumber;
                cityOrder++;
            }

            foreach (var condition in orderedConditionList2.OrderBy(condition => condition.inputNumber).ToList())
            {
                Console.WriteLine($"{condition.prefectureNumber:D6}{condition.cityOrder:D6}");
            }
        }
    }
}