n, m = map(int, input().split())
m -= 1
ans = 0
cnt = 1
while m > 0:
    ans += m
    m //= 2
    cnt += 1
if cnt > n:
    ans = 0
    t = 0
    for i in range(n - 1):
        ans += t
        t = t * 2 + 1
    ans += t
print(ans + n)