You are working on a search tool for a large digital library. Users can search for books or articles based on the first letter of a word. You need to create a program that can extract all the words from a text that starts with a specific letter provided by the user.
The first line of the input contains a letter that the user is interested in. The second line contains the text in which the search will be performed.
The program should output the words that start with the given letter, separated by a space. If no word is found starting with the provided letter, the program should output No words found.
Beaches are the best place to be. Being by the beautiful sea, it's bliss.
Beaches best be Being by beautiful bliss
Note: The program is case-insensitive. For example, if the input letter is b, the program should return words starting with either b or B.