#include<iostream>
#include<vector>
#include<algorithm>
#include<cassert>
#include<atcoder/modint>
using namespace std;
using mint=atcoder::modint998244353;
int M;
vector<mint>solve(vector<int>X)
{
	vector<mint>L(X.size()+1);
	L[0]=1;
	int emp=0;mint coef=1;
	int sum=0;
	for(int i=0;i<X.size();i++)
	{
		if(X[i]==-1)
		{
			if(emp>0)coef*=M;
			emp++;
		}
		else sum=(sum+X[i])%M;
		if(emp>0)L[i+1]=coef;
		else if(sum==0)L[i+1]=1;
	}
	return L;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int T;cin>>T;
	for(;T--;)
	{
		int N;
		cin>>N>>M;
		vector<int>X(N);
		for(int i=0;i<N;i++)cin>>X[i];
		vector<mint>L=solve(X);
		reverse(X.begin(),X.end());
		vector<mint>R=solve(X);
		mint ans=L[N]*(N-1);
		for(int i=1;i<N;i++)ans-=L[i]*R[N-i];
		cout<<ans.val()<<"\n";
	}
}