#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<int,int>;
#define sr string 
#define vc vector
#define db double
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
ll mpow(ll a,ll t,ll m){
	if(t==0)return 1%m;
	ll res=mpow(a,t/2,m);
	res=res*res%m;
	if(t&1)res*=a;
	return res%m;
}
int main(){
    ll n,k;cin>>n>>k;
    vc<pp>v;
    rep(i,n){
    	int l,r;cin>>l>>r;
    	v.pb({l,1});
    	v.pb({r,-1});
    }
    sort(all(v));
    ll m=998244353;
    ll ans=1;
    int now=0;
    for(auto [z,t]:v){
    	if(t==1){
    		ans*=k-now;
    		ans%=m;
    		now++;
    	}
    	else now--;
    }
    ans=(mpow(k,n,m)-ans+m)%m;
    cout<<ans;
}