Problem:
Score : 100 points

Problem Statement

Dolphin loves programming contests. Today, he will take part in a contest in AtCoder.

In this country, 24-hour clock is used. For example, 9:00 p.m. is referred to as "21 o'clock".

The current time is A o'clock, and a contest will begin in exactly B hours.
When will the contest begin? Answer in 24-hour time.

Constraints

0 \leq A,B \leq 23

A and B are integers.

Input

The input is given from Standard Input in the following format:

A B

Output

Print the hour of the starting time of the contest in 24-hour time.

Sample Input 1

9 12

Sample Output 1

21

In this input, the current time is 9 o'clock, and 12 hours later it will be 21 o'clock in 24-hour time.

Sample Input 2

19 0

Sample Output 2

19

The contest has just started.

Sample Input 3

23 2

Sample Output 3

1

The contest will begin at 1 o'clock the next day.

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

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder
{
	public class Program
	{
		static void Main(string[] args)
		{
			var cin = new Scanner2();
			int n = cin.Int();
			int a = cin.Int() - 1;
			int b = cin.Int() - 1;

			var vs = cin.ArrayLong(n);
			Array.Sort(vs);
			Array.Reverse(vs);
			long val = vs[a];
			int preCount = 0;
			int postCount = 0;
			for (int i = a - 1; i >= 0; i--) {
				if (vs[i] == val) {
					preCount++;
				} else {
					break;
				}
			}

			for (int i = a + 1; i < n; i++) {
				if (vs[i] == val) {
					postCount++;
				} else {
					break;
				}
			}

			int count = preCount + 1;
			int allCount = preCount + 1 + postCount;

			bool isAll = true;
			long first = vs[0];
			for (int i = 0; i <= a + postCount; i++) {
				if (first != vs[i]) {
					isAll = false;
					break;
				}
			}

			long ans = 0;
			PascalTriangle.Initialize(50);
			if (isAll) {
				for (int i = a; i <= b; i++) {
					ans += PascalTriangle.Combination(allCount, i + 1);
				}
			} else {
				ans = PascalTriangle.Combination(allCount, count);
			}
			double ave = vs
				.Where((x, index) => index <= a)
				.Select(x => (double)x)
				.Average();
			Console.WriteLine(ave.ToString("f6"));
			Console.WriteLine(ans);
		}
	}

	public static class PascalTriangle
	{
		private static long[,] c_;
		public static void Initialize(int n)
		{
			c_ = new long[n + 1, n + 1];
			for (int i = 0; i <= n; i++) {
				for (int j = 0; j <= i; j++) {
					if (j == 0 || i == j) {
						c_[i, j] = 1;
					} else {
						c_[i, j] = (c_[i - 1, j - 1] + c_[i - 1, j]);
					}
				}
			}
		}

		public static long Combination(long n, long k)
		{
			if (n < k || (n < 0 || k < 0)) {
				return 0;
			}

			return c_[n, k];
		}
	}

	public class Scanner2
	{
		private readonly char[] delimiter_ = new char[] { ' ' };
		private readonly string filePath_;
		private string[] buf_;
		private int index_;
		Func<string> reader_;

		public Scanner2(string file = "")
		{
			if (string.IsNullOrWhiteSpace(file)) {
				reader_ = Console.ReadLine;
			} else {
				filePath_ = file;
				var fs = new StreamReader(file);
				reader_ = fs.ReadLine;
			}
			buf_ = new string[0];
			index_ = 0;
		}

		public string Next()
		{
			if (index_ < buf_.Length) {
				return buf_[index_++];
			}

			string st = reader_();
			while (st == "") {
				st = reader_();
			}

			buf_ = st.Split(delimiter_, StringSplitOptions.RemoveEmptyEntries);
			if (buf_.Length == 0) {
				return Next();
			}

			index_ = 0;
			return buf_[index_++];
		}

		public int Int() => int.Parse(Next());
		public long Long() => long.Parse(Next());
		public double Double() => double.Parse(Next());

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Int() + add;
			}
			return Array;
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Long() + add;
			}
			return Array;
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Double() + add;
			}
			return Array;
		}

		public void Save(string text)
		{
			if (string.IsNullOrWhiteSpace(filePath_)) {
				return;
			}

			File.WriteAllText(filePath_ + "_output.txt", text);
		}
	}
}