using System;

using System.Text;

using System.Linq;

public class Program

{

    public static SearchInput CreateSearchInput(string input)

    {

        var inputSplitted = input.Trim().Split(new [] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

        int number;

        string searchText = "";

        if (int.TryParse(inputSplitted.First(), out number))

        {

            searchText = String.Join(" ", inputSplitted.Skip(1));

        }

        var searchInput = new SearchInput()

        {

            Number = number.ToString(),

            TitleOrBoard = searchText

        };

        return searchInput;

    }

    public static string ConstructSearchQuery(SearchInput searchInput)

    {

        StringBuilder sb = new StringBuilder("SELECT * FROM Books WHERE");

        sb.AppendFormat(" ([Title] LIKE '%{0}%' OR [Board] LIKE '%{0}%')", searchInput.TitleOrBoard);

        if (!String.IsNullOrWhiteSpace(searchInput.Number))

        {

            sb.AppendFormat(" OR Class = '%{0}%'", searchInput.Number);

        }

        return sb.ToString();

    }

    public class SearchInput

    {

        public string TitleOrBoard { get; set; }

        public string Number { get; set; }

    }

    public static void Main()

    {

        string input = "9 English";

        var searchInput = CreateSearchInput(input);

        string sqlQuery = ConstructSearchQuery(searchInput);

        Console.WriteLine("Search: Number[{0}] TitleOrBoard[{1}]", searchInput.Number, searchInput.TitleOrBoard);

        Console.WriteLine("SQL Query: {0}", sqlQuery);

    }

}