import datetime

def mt():
	datime1=
	formatting = 
	datime2 = datime1[:-3]  
	tdelta = datetime.timedelta(hours=12)		
	s3 = datetime.datetime.strptime(datime2, formatting)
	datime2 = s3+tdelta
	print datime2.strftime() + datime1[-3:]

mt()