def test2():
assert last_remaining(5, 2) == 2
assert last_remaining2(5, 2) == 2
def test1():
assert last_remaining(5, 3) == 3
assert last_remaining2(5, 3) == 3
def test6():
assert last_remaining(4000, 997) == 1027
assert last_remaining2(4000, 997) == 1027
def test5():
assert last_remaining(0, 0) == -1
assert last_remaining2(0, 0) == -1
def test4():
assert last_remaining(6, 6) == 3
assert last_remaining2(6, 6) == 3
def test3():
assert last_remaining(6, 7) == 4
assert last_remaining2(6, 7) == 4