#include "bits/stdc++.h"

using namespace std;

#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define double long double

typedef long long ll;
typedef unsigned long long ull;

typedef pair<int,int> ii;
typedef pair<ii,ii> iiii;
typedef pair<ll,int> li;
typedef pair<int,ii> iii;
typedef pair<ii,int> iii2;
typedef pair<ll,ll> pll;
typedef pair<int,ll> il;

ll mod = 1000000007;

const ll large = 1000000000000000000LL;
const int int_large = 1e9;

//begin

ll power(ll a,ll x){
	ll ans = 1;
	while(x){
		if(x&1) ans = ans*a%mod;
		a=a*a%mod;
		x>>=1;
	}
	return ans;
}

struct seg{
	int len,st;
};

void solve(){
	mod = 998244353ll;

	int n,m,s;
	cin>>n>>m>>s;
	vector<ll> d(s,0);
	for(int i=0;i<s;i++) cin>>d[i];
	vector<ll> cnt(s+1,0);

	vector<seg> t(2*s+1,seg());
	int l=s,r=s;

	t[s] = seg{m,0};

	for(int i=0;i<s;i++){
		int g = abs(d[i]);
		if(d[i]>0){
			int remain = min(m,g) ;
			while(remain>0){
				int cur = min(t[r].len,remain);
				remain-=cur;
				t[r].len-=cur;
				cnt[i-t[r].st]+=cur;
				if(t[r].len==0) r--;
			}
			l--;
			t[l] = seg{min(m,g),i+1};

		}else if(d[i]<0){
			int remain = min(m,g) ;
			while(remain>0){
				int cur = min(t[l].len,remain);
				remain-=cur;
				t[l].len-=cur;
				cnt[i-t[l].st]+=cur;
				if(t[l].len==0) l++;
			}
			r++;
			t[r] = seg{min(m,g),i+1};
		}
	}

	for(int i=l;i<=r;i++){
		cnt[s-t[i].st]+=t[i].len;
	}
	//for(int i=0;i<=s;i++) cout<<i<<"!"<<cnt[i]<<endl;

	vector<ll> cnt2(s+1,0);
	for(int i=0;i<=s;i++){
		int d = min(i,n-1);
		if(d) cnt2[d-1]+=2ll*cnt[i];
	}
	for(int i=s-1;i>=0;i--) cnt2[i]+=cnt2[i+1];
	
	for(int i=0;i<=s;i++){
		int dd = max(i,n-1);
		int d = min(i,n-1);

		cnt2[d]+=1ll*(dd+1-d)*cnt[i];
	}

	//for(int i=0;i<=s;i++)  cout<<i<<" "<<cnt2[i]<<endl;

	ll ans = 1;
	for(int i=0;i<=s;i++) ans= ans*power(i+2,cnt2[i])%mod;

	cout<<ans<<endl;

}


int main(){
	fastio;

	int t=1;
	cin>>t;
	while(t--){
		solve();
	}

	return 0;
}