Read spreadsheet without knowing its range

I would like to read a spreadsheet without knowing its range. Is that possible in C#? Or else I have to specify the range till the values are inserted in the sheet?

These things are dynamic in my requirement. The range can be at any limit so my code need to read the entered data from my sheet.

// Create Google Sheets API service.

SheetsService SheetsService = GetSheetsService(); 

// Here is my doubt. 
// I have specified only the sheet name 
// but I dont know the range which could be dynamic

var range = "Sheet3!"; 

SpreadsheetsResource.ValuesResource.GetRequest request = 
    SheetsService.Spreadsheets.Values.Get(SpreadSheetID, range); 

var response = request.Execute(); 
return response;