#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;


int main(){
    int N, K; cin >> N >> K;
    vector<int> L(N), R(N);
    rep(i,N) cin >> L[i] >> R[i];
    vector<int> C(300000);
    rep(i,N){ C[L[i]]++; C[R[i]]--; }
    rep(i,C.size()-1) C[i+1] += C[i];
    Modint rem = 1;
    rep(i,N){ rem *= (N - C[L[i]]); C[L[i]]--; }
    Modint ans = Modint(K).pow(N) - rem;
    cout << ans.val() << endl;
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;