#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N, K;
	cin >> N >> K;
	mint ans_comp = 1;
	vector<pair<int, int>> event;
	for( int i = 0; i < N; i++ ) {
		int L, R;
		cin >> L >> R;
		event.emplace_back(make_pair(L, 1));
		event.emplace_back(make_pair(R, -1));
	}
	sort(event.begin(), event.end());
	mint cnt = 0;
	for( auto& p : event ) {
		if( p.second == 1 ) {
			ans_comp *= K-cnt;
		}
		cnt += p.second;
	}
	cout << (mint(K).pow(N)-ans_comp).val() << endl;
}