N,M = map(int,input().split())
tmp = 1
flag = True
for i in range(1,N):
    tmp *= 2
    if tmp > M:
        flag = False
        break
if flag:
    print(2**N -1)
else:
    List = [M]
    while len(List) < N:
        nx = (List[-1] + 1)//2
        List.append(nx)
        if nx == 1:
            break
    ans = sum(List) + N-len(List)
    print(ans)