#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
int main(){
  int N, K;
  cin >> N >> K;
  vector<int> L(N), R(N);
  for (int i = 0; i < N; i++){
    cin >> L[i] >> R[i];
  }
  vector<tuple<int, int, int>> T(N * 2);
  for (int i = 0; i < N; i++){
    T[i * 2] = make_tuple(L[i], 1, i);
    T[i * 2 + 1] = make_tuple(R[i], 0, i);
  }
  sort(T.begin(), T.end());
  int cnt = 0;
  long long res = 1;
  for (int i = 0; i < N * 2; i++){
    int t = get<1>(T[i]);
    if (t == 0){
      cnt--;
    }
    if (t == 1){
      res *= max(K - cnt, 0);
      res %= MOD;
      cnt++;
    }
  }
  long long all = 1;
  for (int i = 0; i < N; i++){
    all *= K;
    all %= MOD;
  }
  cout << (all - res + MOD) % MOD << endl;
}