#include<bits/stdc++.h>
using namespace std;
using ll = long long;
//using LL = __int128
#define pi pair<ll, ll>
#define fi first
#define se second
//#define fi(x) (x->first)
//#define se(x) (x->second)
#define N 1111111
#define mod 998244353ll
ll n, a[N], m, t, fac[N] = {1};
int main(){
	for(int i = 1 ; i < N ; i++)
		fac[i] = fac[i - 1] * i % mod;
	scanf("%lld", &t);
	while(t--){
		scanf("%lld%lld", &n, &m);
		for(int i = 1 ; i <= m ; i++){
			scanf("%lld", &a[i]);
		}
		if(*min_element(a + 1, a + 1 + m) == 0){
			printf("%lld\n", fac[n]);
			continue;
		}
	}
	return 0;
}
/*
	freopen(".in", "r", stdin);
	freopen(".out", "w", stdout);

*/