Problem:
Score : 200 points

Problem Statement

Print all the integers that satisfies the following in ascending order:

Among the integers between A and B (inclusive), it is either within the K smallest integers or within the K largest integers.

Constraints

1 \leq A \leq B \leq 10^9

1 \leq K \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B K

Output

Print all the integers that satisfies the condition above in ascending order.

Sample Input 1

3 8 2

Sample Output 1

3
4
7
8

3 is the first smallest integer among the integers between 3 and 8.

4 is the second smallest integer among the integers between 3 and 8.

7 is the second largest integer among the integers between 3 and 8.

8 is the first largest integer among the integers between 3 and 8.

Sample Input 2

4 8 3

Sample Output 2

4
5
6
7
8

Sample Input 3

2 9 100

Sample Output 3

2
3
4
5
6
7
8
9

Solution in C# (Mono 4.6.2.0) (judge verdict: Time Limit Exceeded)

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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            ABC093_B();
        }
        static void ABC093_B()
        {
            var ABK = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
            var K = ABK[2];
            var range = Range(ABK[0], ABK[1]+1).ToList();
            var ans = new List<int>();

            if (K >= range.Count)
            {
                foreach (var a in range.OrderBy(x => x))
                    Console.WriteLine(a);
                return;
            }

            for (var i = 0; i < K; i++)
            {
                if (ans.Contains(range[i]))
                    continue;
                ans.Add(range[i]);
            }

            range = range.OrderByDescending(x => x).ToList();
            for (var i = 0; i < K; i++)
            {
                if (ans.Contains(range[i]))
                    continue;
                ans.Add(range[i]);
            }

            foreach (var a in ans.OrderBy(x => x))
                Console.WriteLine(a);
        }

        static IEnumerable<int> Range(int start, int stop)
        {
            if (start < 0 || stop < 0)
                throw new Exception("0未満");

            if (start > stop || (start == 0 && stop == 0))
                return new List<int>();

            return Enumerable.Range(start, stop - start);
        }
    }
}