Count Students By City

student_data is a list of dictionaries, one per student. Every dictionary has a 'rollno' key, a 'city' key, and one key per course holding the marks of that student in the course, for example:

[{'rollno': 1, 'city': 'Chennai', 'maths': 80, 'physics': 60},
 {'rollno': 2, 'city': 'Delhi',   'maths': 55, 'physics': 90}]

Write count_students_by_cities(student_data) that returns a dictionary with the city as key and the number of students from that city as value. The cities appear in the order in which they are first seen in student_data. An empty list gives an empty dictionary.

Example

For [{'rollno': 1, 'city': 'Chennai'}, {'rollno': 2, 'city': 'Delhi'}, {'rollno': 3, 'city': 'Chennai'}] the result is {'Chennai': 2, 'Delhi': 1}.

Your task

Implement this function:

def count_students_by_cities(student_data):

Write the function only — the arguments are read for you and the return value is printed automatically.

Arguments arrive as one Python literal per line, in this order: student_data.

Example

Input

[{'rollno': 1, 'city': 'Chennai'}, {'rollno': 2, 'city': 'Delhi'}, {'rollno': 3, 'city': 'Chennai'}]

Output

{'Chennai': 2, 'Delhi': 1}