def solve():
  N,X = map(int,input().split())
  C = list(map(int,input().split()))
  L,R = [-1] * N,[-1] * N
  for i in range(N):
    c = C[i]
    b = 1 << c
    if X & b == b:
      L[i] = 0
      R[i] = 0
      continue
    r = X % b
    if X > b:
      L[i] = r + 1
    R[i] = b - r
  L.append(0)
  R.append(0)
  ans = max(L) + max(R) * 2
  for l in L:
    if l == -1:
      continue
    for r in R:
      f = 1
      for i in range(N):
        if R[i] > r:
          if L[i] == -1:
            f = 0
          if L[i] > l:
            f = 0
      if f:
        ans = min(ans,l + r + min(l,r))
  print(ans * 2)
  return

for _ in range(int(input())):
  solve()