#include <algorithm>
#include <atcoder/all>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define mod3 100000007
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvb vector<vector<bool>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int, int>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int, int>>
#define vpll vector<pair<ll, ll>>
#define vvpii vector<vector<pair<int, int>>>
#define vvpll vector<vector<pair<ll, ll>>>

template <typename T>
void debug(T e) {
    cerr << e << endl;
}

template <typename T>
void debug(vector<T> &v) {
    rep(i, v.size()) { cerr << v[i] << " "; }
    cerr << endl;
}

template <typename T>
void debug(vector<vector<T>> &v) {
    rep(i, v.size()) {
        rep(j, v[i].size()) { cerr << v[i][j] << " "; }
        cerr << endl;
    }
}

template <typename T>
void debug(vector<pair<T, T>> &v) {
    rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; }
}

template <typename T>
void debug(set<T> &st) {
    for (auto itr = st.begin(); itr != st.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(multiset<T> &ms) {
    for (auto itr = ms.begin(); itr != ms.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(map<T, T> &mp) {
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << H << " ";
    debug_out(T...);
}

using mint = modint998244353;

void debug_mint1(vector<mint> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        cerr << vec[i].val() << " ";
    }
    cerr << endl;
}

void debug_mint2(vector<vector<mint>> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        for (int j = 0; j < vec[i].size(); j++) {
            cerr << vec[i][j].val() << " ";
        }
        cerr << endl;
    }
}

int main() {
    ll N, M;
    cin >> N >> M;
    vector<ll> p(N);
    vector<ll> a(N);
    vector<ll> q(M);
    vector<ll> b(M);
    rep(i, N){
        cin >> p[i] >> a[i];
    }
    rep(i, M){
        cin >> q[i] >> b[i];
    }

    ll L = 200000;
    vector<mint> fact(L + 1);
    fact[0] = mint(1);
    rep(i, L) fact[i + 1] = fact[i] * mint(i + 1);
    vector<mint> finv(L + 1);
    finv[L] = mint(1) / fact[L];
    for (ll i = L - 1; i >= 0; i--){
        finv[i] = finv[i + 1] * mint(i + 1);
    }
    
    ll n_sum = 0;
    ll m_sum = 0;
    rep(i, N) n_sum += a[i];
    rep(i, M) m_sum += b[i];

    // 次数の情報をまとめる
    map<ll, ll> mp1;
    map<ll, ll> mp2;
    map<ll, ll> mp_a;
    map<ll, ll> mp_b;
    rep(i, N){
        mp1[p[i]] = a[i];
        mp_a[p[i]] = a[i];
        mp2[p[i]]++;
    }
    rep(i, M){
        mp1[q[i]] = min(mp1[q[i]], b[i]);
        mp_b[q[i]] = b[i];
        mp2[q[i]]++;
    }
    for (auto it = mp2.begin(); it != mp2.end(); it++){
        if (it->second < 2){
            mp1[it->first] = 0;
        }
    }
    
    vector<pll> ps;
    for (auto it = mp1.begin(); it != mp1.end(); it++){
        ps.push_back(make_pair(it->second, it->first));
    }
    sort(all(ps));

    queue<vector<ll>> que1;
    queue<vector<ll>> que2;
    for (ll i = 0; i < ps.size(); i++){
        ll len = ps[i].first;
        ll val = ps[i].second;

        ll deg_a = mp_a[val];
        ll deg_b = mp_b[val];
        // debug_out(len, val, deg_a, deg_b);

        vector<ll> pows(len + 1);
        pows[0] = 1;
        for (ll j = 0; j < len; j++){
            pows[j + 1] = (pows[j] * val) % mod2;
        }
        vector<ll> vec1(len + 1, 0);
        vector<ll> vec2(len + 1, 0);
        for (ll j = 0; j <= len; j++){
            mint coef = mint(pows[j]) * finv[j] * finv[deg_a - j] * finv[deg_b - j];
            vec1[j] = coef.val();
        }
        for (ll j = 1; j <= len; j++){
            mint coef = mint(pows[j - 1]) * finv[j - 1] * finv[deg_a - j] * finv[deg_b - j];
            vec2[j] = coef.val();
        }
        que1.push(vec1);
        que2.push(vec2);
    }
    
    while (que1.size() > 1){
        vector<ll> v11 = que1.front();
        que1.pop();
        vector<ll> v12 = que1.front();
        que1.pop();
        vector<ll> v1_new = convolution(v11, v12);
        que1.push(v1_new);

        vector<ll> v21 = que2.front();
        que2.pop();
        vector<ll> v22 = que2.front();
        que2.pop();
        vector<ll> v2_new1 = convolution(v21, v12);
        vector<ll> v2_new2 = convolution(v22, v11);
        ll len_sub = v2_new1.size();
        vector<ll> v2_new(len_sub);
        rep(j, len_sub){
            v2_new[j] = (v2_new1[j] + v2_new2[j]) % mod2;
        }
        que2.push(v2_new);
    }
    vector<ll> v1 = que1.front();
    vector<ll> v2 = que2.front();
    ll len_all = v1.size();

    mint ans = mint(0);
    for (ll i = 0; i < len_all; i++){
        ans += mint(v1[i]) * fact[i] * fact[n_sum - i] * fact[m_sum - i];
    }
    for (ll i = 1; i < len_all; i++){
        ans -= mint(v2[i]) * fact[i - 1] * fact[n_sum - i] * fact[m_sum - i];
    }
    cout << ans.val() << endl;
}