def is_only_first_and_last_bit_set(n):
return (((n - 1) & (n - 2)) == 0)
n = 129
print(bin(n))
print(bin(n - 1))
print(bin(n - 2))
print(bin((n - 1) & (n - 2)))
if is_only_first_and_last_bit_set(n):
print("Yes")
else:
print("No")
'''
run:
0b10000001
0b10000000
0b1111111
0b0
Yes
'''