def solve():
n, x = map(int, input().split())
x += 1
a = list(map(int, input().split()))
res = -1
for i in range(30, -1, -1):
b = []
open = False
for j in range(len(a)):
if not open:
b.append(a[j])
else:
b[-1] ^= a[j]
if a[j] & (1 << i):
open = not open
if not (x & (1 << i)):
if open:
print(res)
return
a = b
else:
if not open:
res = max(res, len(b))
print(res)
t = int(input())
for _ in range(t):
solve()
238. Product of Array Except Self | 229. Majority Element II |
222. Count Complete Tree Nodes | 215. Kth Largest Element in an Array |
198. House Robber | 153. Find Minimum in Rotated Sorted Array |
150. Evaluate Reverse Polish Notation | 144. Binary Tree Preorder Traversal |
137. Single Number II | 130. Surrounded Regions |
129. Sum Root to Leaf Numbers | 120. Triangle |
102. Binary Tree Level Order Traversal | 96. Unique Binary Search Trees |
75. Sort Colors | 74. Search a 2D Matrix |
71. Simplify Path | 62. Unique Paths |
50. Pow(x, n) | 43. Multiply Strings |
34. Find First and Last Position of Element in Sorted Array | 33. Search in Rotated Sorted Array |
17. Letter Combinations of a Phone Number | 5. Longest Palindromic Substring |
3. Longest Substring Without Repeating Characters | 1312. Minimum Insertion Steps to Make a String Palindrome |
1092. Shortest Common Supersequence | 1044. Longest Duplicate Substring |
1032. Stream of Characters | 987. Vertical Order Traversal of a Binary Tree |