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

v = M
vls = []

while True:
    vls.append(v)
    if v == 1:
        break
    if v % 2 == 1:
        v = (v+1)//2
    else:
        v = v//2

if len(vls) <= N:
    print(sum(vls)+N-len(vls))
else:
    print(2**(N)-1)