class Solution:
def minBitFlips(self, start: int, goal: int) -> int:
bb = len(bin(max([start, goal]))) - 2
sb = bin(start)[2:].zfill(bb)
gb = bin(goal)[2:].zfill(bb)
d = 0
for i in range(bb):
if sb[i] != gb[i]:
d += 1
return d