#include <iostream>
#include <vector>
#include <cassert>
#include <algorithm>
#define rep(i,n) for(int i=0; i<(int)(n); i++)

using namespace std;
using LL = long long;
using P = pair<int,int>;

const int Max_N = 1e9;
const int Max_K = 1500;
const int Max_M = 2e5;
const LL mod = 998244353;

LL modpow(LL x, LL n){
  LL r = 1;
  while(n){
    if(n & 1) r = r * x % mod;
    x = x * x % mod;
    n >>= 1;
  }
  return r;
}

LL dp[2000][2000][2];
LL sum1[2000][2000][2], sum2[4000][2000][2];

int main(){
  int N, K, M;
  cin >> N >> K >> M;
  assert(1 <= N and N <= Max_N);
  assert(1 <= K and K <= Max_K);
  assert(1 <= M and M <= min(Max_M, K * (K+1) / 2));
  vector<P> S(M);
  vector<int> L(1), R(1);
  vector<bool> erase(M);
  rep(i,M){
    int l, r;
    cin >> l >> r;
    assert(1 <= l and l <= r and r <= K);
    S[i] = P(l, r);
  }
  sort(S.begin(), S.end());
  rep(i,M-1) assert(S[i] != S[i+1]);
  rep(i,M-1) if(S[i+1].second <= S[i].second) erase[i] = true;
  rep(i,M-1){
    if(erase[i]) continue;
    for(int j=i+1; j<M; j++){
      if(S[j].second <= S[i].second){
        erase[i] = true;
        break;
      }
    }
  }
  rep(i,M) if(!erase[i]){
    L.push_back(S[i].first);
    R.push_back(S[i].second);
  }
  M = L.size();
  sum1[0][0][0] = 1, sum2[Max_K][0][0] = 1;
  rep(i,M-1){
    int l = L[i+1], r = R[i+1], d = r - l + 1;
    int pre_r = R[i];
    int s = *(lower_bound(R.begin(), R.end(), l) - 1);
    rep(j,K+1){
      rep(p,2){
        if(j >= d) dp[j][r][p] += sum1[j-d][s][p^1];
        dp[j][r][p] += sum2[j-r+Max_K][pre_r][p^1] - sum2[j-r+Max_K][s][p^1];
        dp[j][r][p] %= mod;
        (sum1[j][r][p] += sum1[j][pre_r][p] + dp[j][r][p]) %= mod;
        (sum2[j-r+Max_K][r][p] += sum2[j-r+Max_K][pre_r][p] + dp[j][r][p]) %= mod;
      }
    }
  }
  vector<LL> power(K+1);
  rep(i,K+1) power[i] = modpow(i, N);
  LL res = 0, ans = 0;
  rep(j,K+1){
    rep(k,K+1){
      rep(p,2) (dp[j][k][p] *= power[K-j]) %= mod;
    }
  }
  rep(j,K+1){
    rep(k,K+1) (res += dp[j][k][1] - dp[j][k][0]) %= mod;
  }
  ans = (modpow(K, N) - res) % mod;
  while(ans < 0) ans += mod;
  cout << ans << endl;

  return 0;
}