import re

def big_letter(file_path):
    pattern = r'^[1-9A-F]0*$'

    with open(file_path, 'r', encoding='utf-8') as file:
        for line in file:
            if re.match(pattern, line.strip()):
                print('yes')
            else:
                print('no')

file_path = 'TaskE10/test.in'
big_letter(file_path)