A compact one line implementation of merge sort!

merge.py

def merge_em(slice):
	return slice if len(slice) == 1 else (lambda first, secon, buffed: (buffed + secon) if map(lambda _: ([buffed.append(secon.pop(_[0])) if two < _[1] else None for two in secon], buffed.append(_[1])), enumerate(first)) or True else None)(*(map(merge_em, (slice[:int(len(slice)/2)], slice[int(len(slice)/2):])) + [[]]))

print merge_em(map(int, raw_input("Enter Subjects: ").strip().split())), raw_input()