import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")

#######################################################################
n,m = na()
k = 0
while m>pow(2,k):
    k += 1

k += 1
ans = 0
if k > n:
    a = 1
    for i in range(n):
        ans += a
        a *= 2
else:
    while m > 1:
        ans += m
        m = (m+1)//2
    ans += n-k+1
print(ans)