n people gathered to hold a jury meeting of the upcoming competition, the i-th member of the jury came up with a_i tasks, which they want to share with each other.

First, the jury decides on the order which they will follow while describing the tasks. Let that be a permutation p of numbers from 1 to n (an array of size n where each integer from 1 to n occurs exactly once).

Then the discussion goes as follows:

  * If a jury member p_1 has some tasks left to tell, then they tell one task to others. Otherwise, they are skipped. 
  * If a jury member p_2 has some tasks left to tell, then they tell one task to others. Otherwise, they are skipped. 
  * ... 
  * If a jury member p_n has some tasks left to tell, then they tell one task to others. Otherwise, they are skipped. 
  * If there are still members with tasks left, then the process repeats from the start. Otherwise, the discussion ends. 



A permutation p is nice if none of the jury members tell two or more of their own tasks in a row. 

Count the number of nice permutations. The answer may be really large, so print it modulo 998 244 353.

Input

The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.

The first line of the test case contains a single integer n (2 ≤ n ≤ 2 ⋅ 10^5) — number of jury members.

The second line contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9) — the number of problems that the i-th member of the jury came up with.

The sum of n over all test cases does not exceed 2 ⋅ 10^5.

Output

For each test case, print one integer — the number of nice permutations, taken modulo 998 244 353.

Example

Input


4
2
1 2
3
5 5 5
4
1 3 3 7
6
3 4 2 1 3 3


Output


1
6
0
540

Note

Explanation of the first test case from the example:

There are two possible permutations, p = [1, 2] and p = [2, 1]. For p = [1, 2], the process is the following:

  1. the first jury member tells a task; 
  2. the second jury member tells a task; 
  3. the first jury member doesn't have any tasks left to tell, so they are skipped; 
  4. the second jury member tells a task. 



So, the second jury member has told two tasks in a row (in succession), so the permutation is not nice.

For p = [2, 1], the process is the following:

  1. the second jury member tells a task; 
  2. the first jury member tells a task; 
  3. the second jury member tells a task. 



So, this permutation is nice.
"""
ID: happyn61
LANG: PYTHON3
PROB: loan
"""
from itertools import product
import itertools
import math
#from collections import defaultdict
import sys
import heapq
from collections import deque
MOD=1000000000007
#fin = open ('loan.in', 'r')
#fout = open ('loan.out', 'w')
#print(dic["4734"])
def find(parent,i):


    if parent[i] != i: 
        parent[i]=find(parent,parent[i]) 
    return parent[i] 

        # A utility function to do union of two subsets 
def union(parent,rank,xx,yy): 
    x=find(parent,xx)
    y=find(parent,yy)
    if rank[x]>rank[y]:
        parent[y]=x
    elif rank[y]>rank[x]:
        parent[x]=y
    else:
        parent[y]=x
        rank[x]+=1
ans=0
#NK=sys.stdin.readline().strip().split()
K=int(sys.stdin.readline().strip())
#N=int(NK[0])
#K=int(NK[1])
#M=int(NK[2])
#ol=list(map(int,sys.stdin.readline().strip().split()))
#d={0:0,1:0}

x=0
y=0

#d={"N":(0,1),"S":(0,-1),"W":(-1,0),"E":(1,0)}
for _ in range(K):
    n=int(sys.stdin.readline().strip())
    s=list(map(int,sys.stdin.readline().strip().split()))
    #print(s)
    s.sort(reverse=True)
    if s[0]==s[1]:
        print(math.factorial(n)%998244353)
    else:
        if s[0]-s[1]>1:
            print(0)
        else:
            k=1
            for i in range(2,n):
                if s[i]==s[1]:
                    k+=1
            #print(n,k)
            #n!-C(n,k+1)*k!*(n-k+1)!
            #C(n,k+1)-c(n-1,k)=C(n-1,k+1)*(n-1)
            #print((math.factorial(n)%998244353-math.factorial(k)%998244353)%998244353)
            print((math.factorial(n)*k//(k+1))%998244353)
    
    
    