n, m = map(int, input().split())

if n <= 60 and m >= pow(2, n - 1):
    print(pow(2, n) - 1)
    exit()

ans = 0
while n > 0 and m != 1:
    ans += m
    if m % 2 == 0:
        m //= 2
    else:
        m += 1
        m //= 2
    n -= 1
ans += n
print(ans)