n,m = map(int,input().split())
cnt = 0
while 2**cnt < m:
    cnt += 1
if n-1 < cnt:
    ans = 2**n-1
else:
    cnt = 0
    ans = m
    while m != 1:
        m = -(-m//2)
        ans += m
        cnt += 1
    ans += n-cnt-1
print(ans)