N,M = map(int,input().split())

import sys
k = 0
while (1 << k) <= M:
    k += 1
if k > N - 1:
    ans = 2 ** N - 1
    print(ans)
    exit()

l = []
while M > 1:
    l.append(M)
    M = (M + 1) // 2
n = len(l)
ans = sum(l) + (N-n)
print(ans)