N,M=map(int,input().split())
K=0
for k in range(1,30):
  if 2**k<=M:
    K=k
result=0
a=N
b=0
for k in range(K,-1,-1):
  if (M>>k)&1:
    if N%2==1:
      result+=(N-1)*(2**k)
      if a>0:
        a-=1
        b+=1
    else:
      result+=N*2**k
  else:
    result+=(b//2)*2**(k+1)
print(result)