#include <bits/stdc++.h>

using namespace std;

const int N = 1010, MOD = 998244353;
inline int Plus(int a, int b) {return a + b >= MOD ? a + b - MOD : a + b; }
inline int Minus(int a, int b) {return a - b < 0 ? a - b + MOD : a - b; }
inline int ksm(long long a, int b) {
	long long r = 1;
	for(; b; b >>= 1, a = a * a % MOD)
		if(b & 1) r = r * a % MOD;
	return r;
}
int n, q, a, L[N], R[N], M[N], up[N], siz[N];
vector<int> lsh;
inline int get(int x) {return lower_bound(lsh.begin(), lsh.end(), x) - lsh.begin() + 1; }

inline void init() {
	for(int i = 1; i < lsh.size(); i ++)
		siz[i] = lsh[i] - lsh[i - 1];
	vector<vector<int>> vec(lsh.size() + 1);
	for(int i = 1; i <= q; i ++) 
		vec[L[i]].emplace_back(M[i]), vec[R[i]].emplace_back(-M[i]);
	map<int, int> Map;
	for(int i = 1; i <= lsh.size(); i ++) {
		for(auto x : vec[i]) {
			if(x > 0) Map[x] ++;
			else if(!--Map[-x]) Map.erase(-x);
		}
		up[i] = (Map.empty() ? -1 : Map.begin()->first);
	}
}

int f[N];
inline int calc_ans(vector<pair<int, int>> &Q, vector<int> &P) {
	int UP = up[*P.begin()];
	for(auto &pr : Q) {
		if(*P.begin() > pr.second || *P.rbegin() < pr.first) return 0;
		pr.first = lower_bound(P.begin(), P.end(), pr.first) - P.begin();
		pr.second = --upper_bound(P.begin(), P.end(), pr.second) - P.begin();
		if(pr.first > pr.second) return 0;
	}
	vector<vector<int>> lim(P.size() + 1);
	for(auto pr : Q) lim[pr.second + 1].emplace_back(pr.first + 1);
	for(int i = 0; i <= P.size(); i ++)
		f[i] = 0;
	f[0] = 1; int bound = 0;
	for(int i = 1; i <= P.size(); i ++) {
		int c1 = ksm(UP, siz[P[i - 1]]), c2 = ksm(UP - 1, siz[P[i - 1]]); c1 = Minus(c1, c2);
		for(int j = bound; j < i; j ++)
			f[i] = Plus(f[i], 1ll * f[j] * c1 % MOD), f[j] = 1ll * f[j] * c2 % MOD;
		if(lim[i].empty()) continue;
		int Lim = lim[i][0];
		for(auto x : lim[i]) Lim = max(Lim, x);
		if(Lim > bound) {
			for(int j = bound; j < Lim; j ++) f[j] = 0;
			bound = Lim;
		}
	}
	int res = 0;
	for(int i = bound; i <= P.size(); i ++)
		res = Plus(res, f[i]);
	return res;
}

inline int calc_ans() {
	map<int, vector<pair<int, int>>> MapQ;
	map<int, vector<int>> MapV;
	for(int i = 1; i <= q; i ++)
		MapQ[M[i]].push_back({L[i], R[i] - 1});
	for(int i = 1; i < lsh.size(); i ++)
		if(up[i] != -1) MapV[up[i]].emplace_back(i);
	int res = 1;
	for(auto &pr : MapQ) {
		if(!MapV.count(pr.first)) return 0;
		res = 1ll * res * calc_ans(pr.second, MapV[pr.first]) % MOD;
	}
	return res;
}

inline void solve() {
	lsh.clear();
	cin >> n >> q >> a;
	for(int i = 1; i <= q; i ++) {
		cin >> L[i] >> R[i] >> M[i]; R[i] ++;
		lsh.emplace_back(L[i]), lsh.emplace_back(R[i]);
	}
	lsh.emplace_back(1), lsh.emplace_back(n + 1);
	sort(lsh.begin(), lsh.end()), lsh.erase(unique(lsh.begin(), lsh.end()), lsh.end());
	for(int i = 1; i <= q; i ++)
		L[i] = get(L[i]), R[i] = get(R[i]);
	init();

	int res = 1;
	for(int i = 1; i < lsh.size(); i ++)
		if(up[i] == -1) res = 1ll * res * ksm(a, siz[i]) % MOD;
	cout << 1ll * res * calc_ans() % MOD << '\n';
}

int main() {
	ios::sync_with_stdio(false), cin.tie(0);
	
	int T; cin >> T;
	while(T --) solve();

	return 0;
}