#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while (tt--) {
    int n, m;
    cin >> n >> m;
    VI x(n);
    rep(i, n) cin >> x[i];
    int i = find(all(x), -1) - x.begin();
    if (i == n) {
      int now = 0;
      int ans = 0;
      for (int x : x) {
        now = (now + x) % m;
        ans += now > 0;
      }
      if (now) ans = 0;
      cout << ans << '\n';
      continue;
    }
    int j = n - 1;
    while (x[j] != -1) j--;
    int cnt = count(all(x), -1);
    mint ans = j - i >= 1 ? mint(j - i) * (m - 1) * mint(m).pow(cnt - 2) : mint();
    mint coeff = mint(m).pow(cnt - 1);
    rep(_, 2) {
      int now = 0;
      for (int x : x) {
        if (x == -1) break;
        now = (now + x) % m;
        if (now) ans += coeff;
      }
      reverse(all(x));
    }
    cout << ans.val() << '\n';
  }
}