print("a b".split())
print("   a   b    ".split(None))
print("   a   b    ".split(None, 1))
print("   a   b    ".split(None, 2))
print("   a   b  c  ".split(None, 1))
print("   a   b  c  ".split(None, 0))
print("   a   b  c  ".split(None, -1))