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

i = 1
for _ in range(n - 1):
    i *= 2
    if i > m:
        break
else:
    print(2 * i - 1)
    exit()
    
ans = 0
for i in range(1, n + 1):
    ans += m
    if m % 2 == 1:
        m += 1
    m //= 2
    if m == 0:
        ans += n - i
        break
print(ans)