c# substring from index to end

//Get a string between a start index and end index    
string str = "How to find a substring in a string";    
int startIndex = 7;    
int endIndex = str.Length - 7;    
string title = str.Substring(startIndex, endIndex);using System; 
class HellWorld { 
  
    // Main Method 
    public static void Main() 
    { 
  
        // define string 
        String str = "Let us code"; 
  
        Console.WriteLine("String    : " + str); 
  
        // retrieve the substring from index 5 
        Console.WriteLine("Sub String1: " + str.Substring(5)); 
  
        // retrieve the substring from index 8 
        Console.WriteLine("Sub String2: " + str.Substring(8)); 
    } 
}