Problem:
Handsel

Alice and Brown are brothers in a family and each receives pocket money in celebration of the coming year. They are very close and share the total amount of the money fifty-fifty. The pocket money each receives is a multiple of 1,000 yen.

Write a program to calculate each one’s share given the amount of money Alice and Brown received.

Input

The input is given in the following format.

a b

A line of data is given that contains two values of money: a (1000 ≤ a ≤ 50000) for Alice and b (1000 ≤ b ≤ 50000) for Brown.

Output

Output the amount of money each of Alice and Brown receive in a line.

Sample Input 1

1000 3000

Sample Output 1

2000

Sample Input 2

5000 5000

Sample Output 2

5000

Sample Input 3

1000 2000

Sample Output 3

1500

Solution in C# (judge verdict: Accepted)

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

namespace _0357
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(RArInt().Sum() / 2);
        }
        static string RSt() { return Console.ReadLine(); }
        static int RInt() { return int.Parse(Console.ReadLine().Trim()); }
        static long RLong() { return long.Parse(Console.ReadLine().Trim()); }
        static double RDouble() { return double.Parse(Console.ReadLine()); }
        static string[] RArSt(char sep = ' ') { return Console.ReadLine().Trim().Split(sep); }
        static int[] RArInt(char sep = ' ') { return Array.ConvertAll(Console.ReadLine().Trim().Split(sep), e => int.Parse(e)); }
        static long[] RArLong(char sep = ' ') { return Array.ConvertAll(Console.ReadLine().Trim().Split(sep), e => long.Parse(e)); }
        static double[] RArDouble(char sep = ' ') { return Array.ConvertAll(Console.ReadLine().Trim().Split(sep), e => double.Parse(e)); }
        static string WAr<T>(IEnumerable<T> array, string sep = " ") { return string.Join(sep, array.Select(x => x.ToString()).ToArray()); }
    }
}