class Solution:
def _right(self, n):
if n == 1:
return 1
if n % 2 == 1:
return 2 * self._left(n // 2)
else:
return 2 * self._left(n // 2) - 1
def _left(self, n):
if n == 1:
return 1
return 2 * self._right(n // 2)
def lastRemaining(self, n: int) -> int:
return self._left(n)