file_1 = open('1.txt', 'r').read().split('\n')
file_2 = open('2.txt', 'r').read().split('\n')
array = []
for email in file_1:
if email.split(':')[0] not in file_2:
array.append(email)
str = ""
for email in array:
str += email
str += '\n'
file_3 = open('3.txt', 'w')
file_3.write(str)