public class Example
{
public static void Main()
{
string txt = "I am stronger than Batman.";
Console.WriteLine(txt);
char[] phraseAsChars = txt.ToCharArray();
int searchIndex = txt.IndexOf("Batman");
if (searchIndex != -1)
{
phraseAsChars[searchIndex++] = 'C';
phraseAsChars[searchIndex++] = 'a';
phraseAsChars[searchIndex++] = 't';
phraseAsChars[searchIndex++] = 'm';
phraseAsChars[searchIndex++] = 'a';
phraseAsChars[searchIndex++] = 'n';
}
string updatedPhrase = new string(phraseAsChars);
Console.WriteLine(updatedPhrase);
}
}