7.00 To Uppercase

// Problem 5. Parse tags

/*  You are given a text. Write a program that changes the text in all regions surrounded by the tags <upcase> and </upcase> to upper-case.
    The tags cannot be nested.

Example: We are living in a <upcase>yellow submarine</upcase>. We don't have <upcase>anything</upcase> else.

The expected result: We are living in a YELLOW SUBMARINE. We don't have ANYTHING else.
 */

using System;
using System.Text.RegularExpressions;

class ParseTags
{
    static void Main()
    {
        string text = Console.ReadLine(); // please comment this line if usiing the line below
                                          //string text = "We are living in a <upcase>yellow submarine</upcase>. We don't have <upcase>anything</upcase> else.";

        // match and print
        Console.WriteLine(Regex.Replace(text, "<upcase>(.*?)</upcase>", word => word.Groups[1].Value.ToUpper()));
    }
}