#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)
using ll = long long;
#define all(p) p.begin(),p.end()

int main(){
	const int mod=998244353;
	ll A=1,B=1;
	ll N,K;
	cin>>N>>K;
	vector<int> p(N*2);
	rep(i,0,N){
		A=(A*K)%mod;
		int a,b;
		cin>>a>>b;
		p[i*2]=a*10;
		p[i*2+1]=b*10-1;
	}
	sort(all(p));
	rep(i,0,N*2){
		if(p[i]%10==0) B=(B*K)%mod,K--;
		else K++;
	}
	cout<<(A-B+mod)%mod<<"\n";
}