def is_phone_number(text):
	if len(text) != 12:
		return False
	for i in range(0,3):
		if not text[i].isdecimal():
			return False
	if text[3] != '-':
		return False
	for i in range(4,7):
		if not text[i].isdecimal():
			return False
	for i in range(8,12):
		if not text[i].isdecimal():
			return False
	return True

# print('Is 415-555-4242 a phone number?')
# print(is_phone_number('415-555-4242'))
# print('Is Moshi moshi a phone number?')
# print(is_phone_number('Moshi moshi'))

message = 'Call me at 415-555-10111 tomorrow. 415-555-9999 is my office.'
for i in range(len(message)):
	chunk = message[i:i+12]
	if is_phone_number(chunk):
		print('Phone number found: ' + chunk)
print('Done')