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

ans = 0
small = [N, 0]
for i in reversed(range(30)):
    if 1<<i & M:
        if N%2 == 0:
            ans += (1<<i)*N
        else:
            ans += (1<<i)*(N-1)
            if small[0]:
                small[0] -= 1
                small[1] += 1
    else:
        ans += (1<<i)*(small[1]//2*2)

print(ans)