import sys
from collections import Counter
def min_operations(n, x, arr):
counter = Counter(arr)
if any(count >= 2 for count in counter.values()):
return 0
for num in arr:
new_num = num & x
if new_num != num and new_num in counter:
return 1
seen = set()
for num in arr:
new_num = num & x
if new_num in seen:
return 2
else:
seen.add(new_num)
return -1
n, x = map(int, input().split())
arr = list(map(int, input().split()))
print(min_operations(n, x, arr))
779. K-th Symbol in Grammar | 701. Insert into a Binary Search Tree |
429. N-ary Tree Level Order Traversal | 739. Daily Temperatures |
647. Palindromic Substrings | 583. Delete Operation for Two Strings |
518. Coin Change 2 | 516. Longest Palindromic Subsequence |
468. Validate IP Address | 450. Delete Node in a BST |
445. Add Two Numbers II | 442. Find All Duplicates in an Array |
437. Path Sum III | 436. Find Right Interval |
435. Non-overlapping Intervals | 406. Queue Reconstruction by Height |
380. Insert Delete GetRandom O(1) | 332. Reconstruct Itinerary |
368. Largest Divisible Subset | 377. Combination Sum IV |
322. Coin Change | 307. Range Sum Query - Mutable |
287. Find the Duplicate Number | 279. Perfect Squares |
275. H-Index II | 274. H-Index |
260. Single Number III | 240. Search a 2D Matrix II |
238. Product of Array Except Self | 229. Majority Element II |