British mathematician John Littlewood once said about Indian mathematician Srinivasa Ramanujan that "every positive integer was one of his personal friends."

It turns out that positive integers can also be friends with each other! You are given an array a of distinct positive integers. 

Define a subarray a_i, a_{i+1}, …, a_j to be a friend group if and only if there exists an integer m ≥ 2 such that a_i mod m = a_{i+1} mod m = … = a_j mod m, where x mod y denotes the remainder when x is divided by y.

Your friend Gregor wants to know the size of the largest friend group in a.

Input

Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 2⋅ 10^4). 

Each test case begins with a line containing the integer n (1 ≤ n ≤ 2 ⋅ 10^5), the size of the array a.

The next line contains n positive integers a_1, a_2, …, a_n (1 ≤ a_i ≤ {10}^{18}), representing the contents of the array a. It is guaranteed that all the numbers in a are distinct.

It is guaranteed that the sum of n over all test cases is less than 2⋅ 10^5.

Output

Your output should consist of t lines. Each line should consist of a single integer, the size of the largest friend group in a.

Example

Input


4
5
1 5 2 4 6
4
8 2 5 10
2
1000 2000
8
465 55 3 54 234 12 45 78


Output


3
3
2
6

Note

In the first test case, the array is [1,5,2,4,6]. The largest friend group is [2,4,6], since all those numbers are congruent to 0 modulo 2, so m=2.

In the second test case, the array is [8,2,5,10]. The largest friend group is [8,2,5], since all those numbers are congruent to 2 modulo 3, so m=3.

In the third case, the largest friend group is [1000,2000]. There are clearly many possible values of m that work.
1
3
1 137438953474 274877906947
 5
1
13
1
1
6
7 19 28 25 4 10
3
3 19 10
9
26 1 28 8 24 27 12 16 17
 1
69
2 4 10 16 22 28 34 40 46 52 58 64 70 76 82 88 94 100 106 112 118 124 130 136 142 148 154 160 166 172 178 184 190 196 202 208 214 220 226 232 238 244 250 256 262 268 274 280 286 292 298 304 310 316 322 328 334 340 346 352 358 364 370 376 382 388 391 397 403
 1
20
1 3 5 7 9 11 13 15 17 19 22 25 28 31 34 37 40 43 46 49
 1
20
16 15 17 8 30 23 20 28 27 6 1 18 24 2 10 5 14 29 12 7
 3
3
14 4 27
13
26 14 6 10 5 3 29 2 24 12 22 11 1
4
10 25 29 11
 1
4
1 140688977775057788 281377955550115575 281377955925200962

3
 1
1
6
2
3
 68
 11
 4
 2
4
3
 4

import sys
input = lambda : sys.stdin.readline().rstrip()

sys.setrecursionlimit(2*10**5+10)
write = lambda x: sys.stdout.write(x+"\n")
debug = lambda x: sys.stderr.write(x+"\n")
writef = lambda x: print("{:.12f}".format(x))

class SG:
    def __init__(self, n, v=None):
        self._n = n
        self.geta = 0
        x = 0
        while (1 << x) < n:
            x += 1
        self._log = x
        self._size = 1 << self._log
        self._d = [ninf] * (2 * self._size)
        if v is not None:
            for i in range(self._n):
                self._d[self._size + i] = v[i]
        for i in range(self._size - 1, 0, -1):
            self._update(i)
    def _update(self, k):
        self._d[k] = op(self._d[2 * k], self._d[2 * k + 1])
    def update(self, p, x):
        assert 0 <= p < self._n
#         x -= self.geta
        p += self._size
        self._d[p] = x
        for i in range(1, self._log + 1):
#             self._update(p >> i)
            k = p>>i
            self._d[k] = op(self._d[2 * k], self._d[2 * k + 1])
    def get(self, p):
        assert 0 <= p < self._n
        return self._d[p + self._size] # + self.geta
    def check(self):
        return [self.get(p) for p in range(self._n)]
    def query(self, left, right):
        # [l,r)の総和
#         assert 0 <= left <= right <= self._n
        sml = ninf
        smr = ninf
        left += self._size
        right += self._size
        while left < right:
            if left & 1:
                sml = op(sml, self._d[left])
                left += 1
            if right & 1:
                right -= 1
                smr = op(self._d[right], smr)
            left >>= 1
            right >>= 1
        return op(sml, smr) # + self.geta
    def query_all(self):
        return self._d[1] # + self.geta
    def max_right(self, left, f):
#         assert 0 <= left <= self._n
#         assert f(ninf)
        if left == self._n:
            return self._n
        left += self._size
        sm = ninf
        first = True
        while first or (left & -left) != left:
            first = False
            while left % 2 == 0:
                left >>= 1
            if not f(op(sm, self._d[left])):
                while left < self._size:
                    left *= 2
                    if f(op(sm, self._d[left])):
                        sm = op(sm, self._d[left])
                        left += 1
                return left - self._size
            sm = op(sm, self._d[left])
            left += 1
        return self._n
    def min_left(self, right, f):
#         assert 0 <= right <= self._n
#         assert f(ninf)
        if right == 0:
            return 0
        right += self._size
        sm = ninf
        first = True
        while first or (right & -right) != right:
            first = False
            right -= 1
            while right > 1 and right % 2:
                right >>= 1
            if not f(op(self._d[right], sm)):
                while right < self._size:
                    right = 2 * right + 1
                    if f(op(self._d[right], sm)):
                        sm = op(self._d[right], sm)
                        right -= 1
                return right + 1 - self._size
            sm = op(self._d[right], sm)
        return 0
    
from math import gcd
op = gcd
ninf = 0

t = int(input())
ans = []
for _ in range(t):
    n = int(input())
    a = list(map(int, input().split()))
    d = [a[i]-a[i-1] for i in range(1,n)]
    sg = SG(n-1, d)
    j = 0
    g = 0
    res = 0
    for i in range(n-1):
        if j<i:
            j = i
            g = 0
        else:
            g = sg.query(i,j)
        while j<n-1 and gcd(g, d[j])>1:
            g = gcd(g, d[j])
            j += 1
        if g>1:
            res = max(res, j-i)
    ans.append(res+1)
write("\n".join(map(str, ans)))