How to convert Task<list> to task<long>

while executing below code getting conversion error :how to covert from task<list<object> to task<long> 

public class EmployeeData
    {
        public static async Task<List<EmployeeData>> GetEmployee()
        {
            List<EmployeeData> EmployeeData = new List<EmployeeData>()
            { 
              new EmployeeData()
              {
               
                    Id = 1,
                    Name="Abc"

                }
            };
            return  EmployeeData;