//g++ 1.cpp -std=c++17 -O2 -I .
#include <bits/stdc++.h>
using namespace std;

#include <atcoder/math>
using namespace atcoder;

using ll = long long;
using ld = long double;
 
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vst = vector<string>;
using vvst = vector<vst>;
 
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define pq_big(T) priority_queue<T,vector<T>,less<T>>
#define pq_small(T) priority_queue<T,vector<T>,greater<T>>
#define all(a) a.begin(),a.end()
#define rep(i,start,end) for(ll i=start;i<(ll)(end);i++)
#define per(i,start,end) for(ll i=start;i>=(ll)(end);i--)
#define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end())

constexpr ll mod = 998244353;

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int n;ll k;
  cin>>n>>k;

  int now=0;
  vector<tuple<int,int,int>> t; // time,id, open or leave
  rep(i,0,n){
    int l,r;cin>>l>>r;
    t.emplace_back(l,i,1);
    t.emplace_back(r,i,0);
  }

  sort(all(t));

  ll ans=1;
  for(auto [time,id,op]:t){
    if(op==0){
      now--;
    }
    else{
      if(k<=now)ans=0;
      ans*=k-now;
      ans%=mod;
      now++;
    }
  }

  ans=pow_mod(k,n,mod)-ans;
  ans%=mod;
  if(ans<0)ans+=mod;

  cout<<ans<<endl;
}