#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

ll pow_mod(ll x, ll n, ll mod){
    ll ret = 1;
    while(n > 0){
        if(n & 1) ret = (ret*x)%mod;
        x = x*x%mod;
        n >>=1;
    }
    return ret;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll n, k;
    cin >> n >> k;

    priority_queue<pll, vector<pll>, greater<pll>> PQ;
    rep(i, n){
        ll L, R;
        cin >> L >> R;
        R--;
        PQ.push({L, 0});
        PQ.push({R, 1});
    }

    ll cnt = 0;
    ll ans = 1;
    while(!PQ.empty()){
        ll y = PQ.top().se;
        PQ.pop();

        if(y == 0){
            ans = (ans * max(k-cnt, 0LL))%MOD2;
            cnt++;
        }else{
            cnt--;
        }
    }

    cout << (pow_mod(k, n, MOD2)-ans+MOD2)%MOD2 << endl;
}