# -*- coding: utf-8 -*-
"""
Created on Fri May 21 21:50:54 2021

@author: PC
"""

import re

import os
os.chdir(r'C:\Users\PC\Pytho')
def grades():
    with open ("grades.txt", "r") as file:
        grades = file.read()

    students= re.findall('([A-Z][a-z]+ [A-Z][a-z]+): B',grades)
    #raise NotImplementedError()
    return students
    
print(grades())
print(len(grades()))    
    
assert len(grades()) == 16