Problem:
Score : 100 points

Problem Statement

On some day in January 2018, Takaki is writing a document. The document has a column where the current date is written in yyyy/mm/dd format. For example, January 23, 2018 should be written as 2018/01/23.

After finishing the document, she noticed that she had mistakenly wrote 2017 at the beginning of the date column. Write a program that, when the string that Takaki wrote in the date column, S, is given as input, modifies the first four characters in S to 2018 and prints it.

Constraints

S is a string of length 10.

The first eight characters in S are 2017/01/.

The last two characters in S are digits and represent an integer between 1 and 31 (inclusive).

Input

Input is given from Standard Input in the following format:

S

Output

Replace the first four characters in S with 2018 and print it.

Sample Input 1

2017/01/07

Sample Output 1

2018/01/07

Sample Input 2

2017/01/31

Sample Output 2

2018/01/31

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

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

namespace AtCoder
{
	class Program
	{
		static void Main(string[] args)
		{
			Question.Exec();
		}
	}

	public static class Question
	{
		public static bool IsOdd(long n)
		{
			bool isOdd = n % 2 == 1;
			return isOdd;
		}

		public static void Exec()
		{
			string str = Console.ReadLine();
			str = str.Replace("2017", "2018");
			Console.WriteLine($"{str}");

			Console.ReadKey();
		}

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

			public Scanner(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;
			}
		}
	}
}