for _ in range(int(input())):
  x, y = map(int, input().split())
  if x & (1 << y) == 0:
    print(0)
    continue
  k = x | ((1 << y) - 1)
  ans = 1 << y
  for i in reversed(range(y)):
    if k & (1 << i) == 0:
      break
    ans += 1 << i
  for i in range(y+1, 60):
    if k & (1 << i) == 0:
      break
    ans += 1 << i
  print(ans)