#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
template<typename T> inline bool chmax(T &a, T b) { return ((a < b) ? (a = b, true) : (false)); }
template<typename T> inline bool chmin(T &a, T b) { return ((a > b) ? (a = b, true) : (false)); }
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
#define rep2(i, m ,n) for (int i = (m); i < (long long)(n); i++)
#define REP(i, n) for (long long i = 1; i < (long long)(n); i++)
typedef long long ll;
#define updiv(N,X) (N + X - 1) / X
#define l(n) n.begin(),n.end()
#define YesNo(Q) Q==1?cout<<"Yes":cout<<"No"
using P = pair<int, int>;
using mint = modint;
const int MOD = 998244353LL;
const ll INF = 999999999999LL;
vector<long long> fact, fact_inv, inv;
/*  init_nCk :二項係数のための前処理
    計算量:O(n)
*/
template <typename T>
void input(vector<T> &v){
 rep(i,v.size()){cin>>v[i];}
  return;
}
void init_nCk(int SIZE) {
    fact.resize(SIZE + 5);
    fact_inv.resize(SIZE + 5);
    inv.resize(SIZE + 5);
    fact[0] = fact[1] = 1;
    fact_inv[0] = fact_inv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < SIZE + 5; i++) {
        fact[i] = fact[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
        fact_inv[i] = fact_inv[i - 1] * inv[i] % MOD;
    }
}
/*  nCk :MODでの二項係数を求める(前処理 int_nCk が必要)
    計算量:O(1)
*/
long long nCk(int n, int k) {
    assert(!(n < k));
    assert(!(n < 0 || k < 0));
    return fact[n] * (fact_inv[k] * fact_inv[n - k] % MOD) % MOD;
}

long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

ll POW(ll a,ll n){
  long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a;
        a = a * a;
        n >>= 1;
    }
    return res;
}
int main() {
 int t;cin>>t;
 while(t--){
 	ll n;cin>>n;
 	ll m;cin>>m;vector<ll> v(n);rep(i,n){cin>>v[i];}
 	ll cnt = 0;ll cnt2 = 0;mint ans = 0;
    ll cnt3 = 0;ll cnt4 = 0;
    rep(i,n){if(v[i]==-1){cnt3++;}else{cnt4 += v[i];}}
    rep(i,n){
    if(v[i]==-1){cnt3--;}else{cnt4 -= v[i];}
    if(v[i]==-1){cnt++;}else{cnt2 += v[i];}
    mint res = 1;
    if(cnt==0){if(cnt2%m!=0){res *= 0;}}
    else{res *= modpow(m,cnt-1,998244353LL);}
    if(cnt3==0){if(cnt4%m!=0){res *= 0;}}
    else{res *= modpow(m,cnt3-1,998244353LL);}
    ans += res;
    }
    mint res5 = 0;
  //  cout << ans.val() << endl;
    if(cnt==0){
    	if(cnt2%m==0){res5 = n;}
    	else{cout << 0 << endl;continue;}
    }
    else{
    	res5 = n*modpow(m,cnt-1,998244353LL);
    }
    cout << (res5-ans).val() << endl;
 }
}