ชื่อและตำแหน่งหัวหน้าแผนกที่มีจำนวนพนักงานน้อยที่สุดคือข้อใด
what is the name and position of the head whose department has least number of employees?
{'department': {'head': 'string'}, 'physician': {'name': 'string', 'position': 'string', 'EmployeeID': 'string'}}
emp_id_of_least_emp_dept = df['department'].groupby('head').size().idxmin(); df['physician'][df['physician']['EmployeeID']==emp_id_of_least_emp_dept][['name', 'position']]