using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("{0}", Contains("man","hello man, what's up?"));

        Console.WriteLine("{0}", Contains("hello","hello man, what's up?"));

        Console.WriteLine("{0}", Contains("yeah","hello man, what's up?"));

    }

    public static bool Contains(string query, string text){

        var isFound = false;

        int i = 0;

        int j = 0;

        // we loop through each character of the text, not of the query

        while(i < text.Length && !isFound){

            j = 0;

            while(j < query.Length){

                // note the i+j to check the following letters

                if(text[i + j] != query[j]){

                    break;

                }

                j++;

            }

            // if we checked all the characters of the query

            isFound = j >= query.Length;

            i++;

        }

        return isFound;

    }

}