using System;

using System.Globalization;     

using System.Collections.Generic;

​

public class RowItem {

    public string Line {get;set;}   

}

​

public class Program

{

    public static void Main()

    {

        var list = new List<RowItem>();

        char character = 'X';

        var rows = 3;

        var charactersPerRow = 5;

        for(var i = 0; i < rows; i++) 

        {

            list.Add(new RowItem {

                Line = new String(character, charactersPerRow),

            });

        }

        foreach(var item in list) {

            Console.WriteLine(item.Line);   

        }

    }

}