Implement a WPF app to list stock information that is loaded from StockData.csv. Your app should allow users to Search a specific companys stock information, and display the search result in a DataGrid, and the result should be sorted according to the date. Clean the data by removing those rows that the price contains negative value while the data is loading. Your app should also allow users to calculate the factorial number. The factorial number calculation should not block users to interact with your app.