N,M=map(int, input().split())
if N==1:
  print(0)
  exit()
  
if N%2==0:
  print(M*N)
  exit()
  
ans=0;c=0
for i in range(29,-1,-1):
  if M&(1<<i):
    c=min(c+1,N)
    ans+=pow(2,i)*(N-1)
  else:
    ans+=(c//2)*pow(2,i+1)
print(ans)