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

def main():
    
    mod=1000000007
    # mod=998244353
    # nCr =  make_nCr_mod()
    
    tc=ri()
    for _ in range(tc):
        n=ri()
        a=[0]+ria()
        b=[0]*(n+1)
        
        for i in range(1,n+1):
            b[i]=abs(a[i]-a[i-1])
        
        Table=SparseTable(b,gcd)
        
        ans=1
        
        l,r=2,n
        
        while l<=r:
            mid=(l+r)//2
            flag=False
            for i in range(1,n-mid+2):
                left,right=i+1,i+mid-1
                val=Table.query(left,right)
                if val!=1:
                    flag=True
                    break
            if flag:
                ans=mid
                l= mid +1
            else:
                r= mid -1
        wi(ans)
        
        

def rant():
    # RANT BEGINS-
    # 
    # Did you look at the constraints dummy? Read problem again carefully understand it correctly
    # Are base cases correct n=0,n=1,n=N or string is all 0 or all 1?
    # 
    # 1.Greedy? What matters what doesnt? Is my claim correct? 
    #   Does my implementation correctly implements the greedy i thought of? 
    #   Dictionary? keep a count of values if constraint on something is low(like only alphabets(26) count)? 
    # 
    # 2.DP? Think about state's ranges maybe one of the states have lesser possible values than it may look like? 
    #   Obviously think about order of evaluation
    # 
    # 3.Binary Search?(Monotonic? any one directed order in which we have to perform something?)
    # 
    # 4.Graph?DSU?Edge property or Vertex property Read carefully? Bipartitenes Property??? Cycle Property??? 
    #   Hidden but dependency ordering of values(in 1d array or 2d Table/Array) is that of a graph???
    # 
    # 5.Number Theory?(GCD subtraction?)
    # 
    # 6.Bruteforce?(Redundant part of N which may not give answer?Constraints?)
    # 
    # 7.Range Queries?
    # 
    # 8.Any Equivalency?(We have A and B and have to do 
    #   something between them maybe difficult if there was A~C and C~B then A~B
    #   C could be max or min or some other thing)
    # 
    # 9.Reverse Engineering?(From Answer to quesn or last step to first step)
    #
    # 10.Constructive? Mod? Bruteforce for smaller case and analyze patterns?
    #
    # 11.String? Constructive Greedy example- 
    #   Bracket sequence make first part unknown open and second part unknown closed 
    #   Remember always only n//2 open and n//2 closed brackets are there
    #
    # 12.Combinatorics?--> (n to i-1 index ways) * (ith index ways) * Ways (for i-1 till 0 index)?
    #
    # 13.Look for patterns and dependency of the patterns(maybe only first row or column matters to construct other rows and columns)
    #   for smaller cases maybe make bruteforce solution and analyze the patterns
    # 
    # RANT ENDS
    return "AAAAAAAAAAAAAAAAARRRGHHHHHHHHHHHHHHHHHHHHHHHH"
    
def SieveOfEratosthenes(limit):
    """Returns all primes not greater than limit."""
    isPrime = [True]*(limit+1)
    isPrime[0] = isPrime[1] = False
    primes = []
    for i in range(2, limit+1):
        if not isPrime[i]:continue
        primes += [i]
        for j in range(i*i, limit+1, i):
            isPrime[j] = False
    return primes

def gcd(x, y):
    """greatest common divisor of x and y"""
    while y:
        x, y = y, x % y
    return x

def memodict(f):
    """memoization decorator for a function taking a single argument"""
    class memodict(dict):
        def __missing__(self, key):
            ret = self[key] = f(key)
            return ret

    return memodict().__getitem__

def pollard_rho(n):
    """returns a random factor of n"""
    if n & 1 == 0:
        return 2
    if n % 3 == 0:
        return 3

    s = ((n - 1) & (1 - n)).bit_length() - 1
    d = n >> s
    for a in [2, 325, 9375, 28178, 450775, 9780504, 1795265022]:
        p = pow(a, d, n)
        if p == 1 or p == n - 1 or a % n == 0:
            continue
        for _ in range(s):
            prev = p
            p = (p * p) % n
            if p == 1:
                return gcd(prev - 1, n)
            if p == n - 1:
                break
        else:
            for i in range(2, n):
                x, y = i, (i * i + 1) % n
                f = gcd(abs(x - y), n)
                while f == 1:
                    x, y = (x * x + 1) % n, (y * y + 1) % n
                    y = (y * y + 1) % n
                    f = gcd(abs(x - y), n)
                if f != n:
                    return f
    return n

@memodict
def prime_factors(n):
    """returns a Counter of the prime factorization of n"""
    if n <= 1:
        return Counter()
    f = pollard_rho(n)
    return Counter([n]) if f == n else prime_factors(f) + prime_factors(n // f)

def distinct_factors(n):
    """returns a list of all distinct factors of n"""
    factors = [1]
    for p, exp in prime_factors(n).items():
        factors += [p**i * factor for factor in factors for i in range(1, exp + 1)]
    return factors

def all_factors(n):
    """returns a sorted list of all distinct factors of n"""
    small, large = [], []
    for i in range(1, int(n**0.5) + 1, 2 if n & 1 else 1):
        if not n % i:
            small.append(i)
            large.append(n // i)
    if small[-1] == large[-1]:
        large.pop()
    large.reverse()
    small.extend(large)
    return small

def make_nCr_mod(max_n=2 * 10**5, mod=10**9 + 7):
    max_n = min(max_n, mod - 1)

    fact, inv_fact = [0] * (max_n + 1), [0] * (max_n + 1)
    fact[0] = 1
    for i in range(max_n):
        fact[i + 1] = fact[i] * (i + 1) % mod

    inv_fact[-1] = pow(fact[-1], mod - 2, mod)
    for i in reversed(range(max_n)):
        inv_fact[i] = inv_fact[i + 1] * (i + 1) % mod

    def nCr_mod(n, r):
        res = 1
        while n or r:
            a, b = n % mod, r % mod
            if a < b:
                return 0
            res = res * fact[a] % mod * inv_fact[b] % mod * inv_fact[a - b] % mod
            n //= mod
            r //= mod
        return res

    return nCr_mod

class DisjointSetUnion:
    def __init__(self, n):
        self.parent = [*range(n+1)]
        self.size = [1]*(n+1)
        self.min, self.max = [*range(n+1)], [*range(n+1)]
        self.count = n

    def get(self, a):
        """Returns the identifier (parent) of the set to which a belongs to!"""
        if self.parent[a] == a:
            return a
        x = a
        while a != self.parent[a]:
            a = self.parent[a]
        while x != self.parent[x]:
            self.parent[x], x = a, self.parent[x]
        return a

    def union(self, a, b):
        """Join two sets that contain a and b!"""
        a, b = self.get(a), self.get(b)
        if a != b:
            if self.size[a] > self.size[b]:
                a, b = b, a
            self.parent[a] = b
            self.size[b] += self.size[a]
            self.min[b] = min(self.min[a], self.min[b])
            self.max[b] = max(self.max[a], self.max[b])
            self.count -= 1

    def count_sets(self):
        """Returns the number of disjoint sets!"""
        return self.count
    
class SegTree:
    
    def __init__(self, n):
        self.N = 1 << n.bit_length()
        self.tree = [0] * (self.N<<1)
    
    def update(self, i, j, v):
        i += self.N
        j += self.N
        while i <= j:
            if i%2==1: self.tree[i] += v
            if j%2==0: self.tree[j] += v
            i, j = (i+1) >> 1, (j-1) >> 1
    
    def query(self, i):
        v = 0
        i += self.N
        while i > 0:
            v += self.tree[i]
            i >>= 1
        return v

class SparseTable:
    def __init__(self, data, func=min):
        self.func = func
        self._data = _data = [list(data)]
        i, n = 1, len(_data[0])
        while 2 * i <= n:
            prev = _data[-1]
            _data.append([func(prev[j], prev[j + i]) for j in range(n - 2 * i + 1)])
            i <<= 1

    def query(self, start, stop):
        """func of data[start, stop)]"""
        depth = (stop + 1 - start).bit_length() - 1
        return self.func(self._data[depth][start], self._data[depth][stop + 1 - (1 << depth)])

    def __getitem__(self, idx):
        return self._data[0][idx]
              
class SortedList:
    def __init__(self, iterable=[], _load=200):
        """Initialize sorted list instance."""
        values = sorted(iterable)
        self._len = _len = len(values)
        self._load = _load
        self._lists = _lists = [values[i:i + _load] for i in range(0, _len, _load)]
        self._list_lens = [len(_list) for _list in _lists]
        self._mins = [_list[0] for _list in _lists]
        self._fen_tree = []
        self._rebuild = True
 
    def _fen_build(self):
        """Build a fenwick tree instance."""
        self._fen_tree[:] = self._list_lens
        _fen_tree = self._fen_tree
        for i in range(len(_fen_tree)):
            if i | i + 1 < len(_fen_tree):
                _fen_tree[i | i + 1] += _fen_tree[i]
        self._rebuild = False
 
    def _fen_update(self, index, value):
        """Update `fen_tree[index] += value`."""
        if not self._rebuild:
            _fen_tree = self._fen_tree
            while index < len(_fen_tree):
                _fen_tree[index] += value
                index |= index + 1
 
    def _fen_query(self, end):
        """Return `sum(_fen_tree[:end])`."""
        if self._rebuild:
            self._fen_build()
 
        _fen_tree = self._fen_tree
        x = 0
        while end:
            x += _fen_tree[end - 1]
            end &= end - 1
        return x
 
    def _fen_findkth(self, k):
        """Return a pair of (the largest `idx` such that `sum(_fen_tree[:idx]) <= k`, `k - sum(_fen_tree[:idx])`)."""
        _list_lens = self._list_lens
        if k < _list_lens[0]:
            return 0, k
        if k >= self._len - _list_lens[-1]:
            return len(_list_lens) - 1, k + _list_lens[-1] - self._len
        if self._rebuild:
            self._fen_build()
 
        _fen_tree = self._fen_tree
        idx = -1
        for d in reversed(range(len(_fen_tree).bit_length())):
            right_idx = idx + (1 << d)
            if right_idx < len(_fen_tree) and k >= _fen_tree[right_idx]:
                idx = right_idx
                k -= _fen_tree[idx]
        return idx + 1, k
 
    def _delete(self, pos, idx):
        """Delete value at the given `(pos, idx)`."""
        _lists = self._lists
        _mins = self._mins
        _list_lens = self._list_lens
 
        self._len -= 1
        self._fen_update(pos, -1)
        del _lists[pos][idx]
        _list_lens[pos] -= 1
 
        if _list_lens[pos]:
            _mins[pos] = _lists[pos][0]
        else:
            del _lists[pos]
            del _list_lens[pos]
            del _mins[pos]
            self._rebuild = True
 
    def _loc_left(self, value):
        """Return an index pair that corresponds to the first position of `value` in the sorted list."""
        if not self._len:
            return 0, 0
 
        _lists = self._lists
        _mins = self._mins
 
        lo, pos = -1, len(_lists) - 1
        while lo + 1 < pos:
            mi = (lo + pos) >> 1
            if value <= _mins[mi]:
                pos = mi
            else:
                lo = mi
 
        if pos and value <= _lists[pos - 1][-1]:
            pos -= 1
 
        _list = _lists[pos]
        lo, idx = -1, len(_list)
        while lo + 1 < idx:
            mi = (lo + idx) >> 1
            if value <= _list[mi]:
                idx = mi
            else:
                lo = mi
 
        return pos, idx
 
    def _loc_right(self, value):
        """Return an index pair that corresponds to the last position of `value` in the sorted list."""
        if not self._len:
            return 0, 0
 
        _lists = self._lists
        _mins = self._mins
 
        pos, hi = 0, len(_lists)
        while pos + 1 < hi:
            mi = (pos + hi) >> 1
            if value < _mins[mi]:
                hi = mi
            else:
                pos = mi
 
        _list = _lists[pos]
        lo, idx = -1, len(_list)
        while lo + 1 < idx:
            mi = (lo + idx) >> 1
            if value < _list[mi]:
                idx = mi
            else:
                lo = mi
 
        return pos, idx
 
    def add(self, value):
        """Add `value` to sorted list."""
        _load = self._load
        _lists = self._lists
        _mins = self._mins
        _list_lens = self._list_lens
 
        self._len += 1
        if _lists:
            pos, idx = self._loc_right(value)
            self._fen_update(pos, 1)
            _list = _lists[pos]
            _list.insert(idx, value)
            _list_lens[pos] += 1
            _mins[pos] = _list[0]
            if _load + _load < len(_list):
                _lists.insert(pos + 1, _list[_load:])
                _list_lens.insert(pos + 1, len(_list) - _load)
                _mins.insert(pos + 1, _list[_load])
                _list_lens[pos] = _load
                del _list[_load:]
                self._rebuild = True
        else:
            _lists.append([value])
            _mins.append(value)
            _list_lens.append(1)
            self._rebuild = True
 
    def discard(self, value):
        """Remove `value` from sorted list if it is a member."""
        _lists = self._lists
        if _lists:
            pos, idx = self._loc_right(value)
            if idx and _lists[pos][idx - 1] == value:
                self._delete(pos, idx - 1)
 
    def remove(self, value):
        """Remove `value` from sorted list; `value` must be a member."""
        _len = self._len
        self.discard(value)
        if _len == self._len:
            raise ValueError('{0!r} not in list'.format(value))
 
    def pop(self, index=-1):
        """Remove and return value at `index` in sorted list."""
        pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
        value = self._lists[pos][idx]
        self._delete(pos, idx)
        return value
 
    def bisect_left(self, value):
        """Return the first index to insert `value` in the sorted list."""
        pos, idx = self._loc_left(value)
        return self._fen_query(pos) + idx
 
    def bisect_right(self, value):
        """Return the last index to insert `value` in the sorted list."""
        pos, idx = self._loc_right(value)
        return self._fen_query(pos) + idx
 
    def count(self, value):
        """Return number of occurrences of `value` in the sorted list."""
        return self.bisect_right(value) - self.bisect_left(value)
 
    def __len__(self):
        """Return the size of the sorted list."""
        return self._len
 
    def __getitem__(self, index):
        """Lookup value at `index` in sorted list."""
        pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
        return self._lists[pos][idx]
 
    def __delitem__(self, index):
        """Remove value at `index` from sorted list."""
        pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
        self._delete(pos, idx)
 
    def __contains__(self, value):
        """Return true if `value` is an element of the sorted list."""
        _lists = self._lists
        if _lists:
            pos, idx = self._loc_left(value)
            return idx < len(_lists[pos]) and _lists[pos][idx] == value
        return False
 
    def __iter__(self):
        """Return an iterator over the sorted list."""
        return (value for _list in self._lists for value in _list)
 
    def __reversed__(self):
        """Return a reverse iterator over the sorted list."""
        return (value for _list in reversed(self._lists) for value in reversed(_list))
 
    def __repr__(self):
        """Return string representation of sorted list."""
        return 'SortedList({0})'.format(list(self))

import sys, os, io
def rs(): return sys.stdin.readline().rstrip()
def ri(): return int(sys.stdin.readline())
def ria(): return list(map(int, sys.stdin.readline().split()))
def ws(s): sys.stdout.write(s + '\n')
def wi(n): sys.stdout.write(str(n) + '\n')
def wia(a): sys.stdout.write(' '.join([str(x) for x in a]) + '\n')
import math,datetime,functools,itertools,operator,bisect,fractions,statistics
from math import log2
from bisect import bisect_left,bisect_right
from collections import deque,defaultdict,OrderedDict,Counter
from fractions import Fraction
from decimal import Decimal
from sys import stdout
from heapq import heappush, heappop, heapify ,_heapify_max,_heappop_max,nsmallest,nlargest
# sys.setrecursionlimit(111111) 
INF=999999999999999999999999
alphabets="abcdefghijklmnopqrstuvwxyz"

class FastReader(io.IOBase):
    newlines = 0

    def __init__(self, fd, chunk_size=1024 * 8):
        self._fd = fd
        self._chunk_size = chunk_size
        self.buffer = io.BytesIO()

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, self._chunk_size))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self, size=-1):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, self._chunk_size if size == -1 else size))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

class FastWriter(io.IOBase):

    def __init__(self, fd):
        self._fd = fd
        self.buffer = io.BytesIO()
        self.write = self.buffer.write

    def flush(self):
        os.write(self._fd, self.buffer.getvalue())
        self.buffer.truncate(0), self.buffer.seek(0)

class FastStdin(io.IOBase):
    def __init__(self, fd=0):
        self.buffer = FastReader(fd)
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

class FastStdout(io.IOBase):
    def __init__(self, fd=1):
        self.buffer = FastWriter(fd)
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.flush = self.buffer.flush

if __name__ == '__main__':
    sys.stdin = FastStdin()
    sys.stdout = FastStdout()
    starttime=datetime.datetime.now()
    if(os.path.exists('input.txt')):
        sys.stdin = open("input.txt","r")
        sys.stdout = open("output.txt","w")
    main()
    endtime=datetime.datetime.now()
    time=(endtime-starttime).total_seconds()*1000
    if(os.path.exists('input.txt')):
        print("Time:",time,"ms")  
    