#include <bits/stdc++.h>

using namespace std;

const int P = 998244353;
const long long INF = 2e18;

void simpl(vector<long long> &x) {
    sort(x.begin(), x.end()), x.erase(unique(x.begin(), x.end()), x.end());
}

typedef pair<long long, long long> Info;

long long calcCC(long long n, vector<long long> &D) {
    priority_queue<Info, vector<Info>, greater<Info> > pq;
    for (auto x : D) {
        if (x) pq.push({x, x});
    }
    D.clear();
    long long dlt = 0, res = 0;
    while (!pq.empty()) {
        auto [d0, ori] = pq.top(); pq.pop();
        d0 -= dlt;
        if (!d0 || d0 >= n) continue;
        D.push_back(ori);
        long long d1 = pq.empty() ? INF : pq.top().first - dlt, v = min(d1, n) / d0 * d0;
        dlt += v, n -= v, pq.push({d0 + dlt, ori});
        if (d0 > n) {
            res = (res + d0 - n) % P;
        }
    }
    simpl(D);
    return (res + n) % P;
}

typedef vector<long long> Bundle;
typedef vector<Bundle> Meta;

vector<Info> getCC(long long n, vector<long long> D, Bundle x) {
    priority_queue<long long, vector<long long>, greater<long long> > pq(D.begin(), D.end());
    long long dlt = 0;
    int m = x.size();
    vector<Info> res;
    for (int i = 0; i < m; ++i) res.push_back({x[i], x[i]});
    while (!pq.empty()) {
        auto d0 = pq.top(); pq.pop();
        d0 -= dlt;
        if (!d0 || d0 >= n) continue;
        long long tn = n, d1 = pq.empty() ? INF : pq.top() - dlt, v = min(d1, n) / d0 * d0;
        dlt += v, n -= v, pq.push(d0 + dlt);
        for (auto &[a, b] : res) {
            if (a >= tn || (a < d0 || a < n)) continue;
            a -= (a - max(n, d0)) / d0 * d0;
            if (a >= d0 && a >= n) a -= d0;
        }
    }
    return res;
}

long long n, res;
vector<long long> ta;
vector< vector<long long> > D = {{}};
vector< array<long long, 3> > E2;

Meta split(int ver, Bundle x) {
    if (x.empty()) return {};
    Meta ret;
    vector<Info> now = getCC(n, D[ver], x), z;
    sort(now.begin(), now.end());
    auto Rside = [&](auto vec) {
        Bundle Ret;
        for (auto [a, b] : vec) Ret.push_back(b);
        return Ret;
    };
    for (auto [fi, se] : now) {
        if (!z.empty() && fi != z.back().first) {
            ret.push_back(Rside(z));
            z.clear();
        }
        z.push_back({fi, se});
    }
    ret.push_back(Rside(z));
    return ret;
}

void solve(int L, int R, Meta x) {
    if (L > R || x.empty()) return;
    if (L == R) {
        for (auto tx : x) {
            for (auto y : tx) {
                if (y != tx[0]) res -= ta[L], E2.push_back({ta[L], y, tx[0]});
            }
        }
        return;
    }
    int mid = (L + R) >> 1;
    Meta le, ri;
    for (auto tx : x) {
        Meta dta = split(mid, tx);
        for (auto y : dta) le.push_back(y);
        Bundle pnt;
        for (auto y : dta) pnt.push_back(y[0]);
        if (!pnt.empty()) ri.push_back(pnt);
    }
    solve(L, mid, le), solve(mid + 1, R, ri);
}

signed main() {
    int m1, m2; scanf("%lld%d%d", &n, &m1, &m2);
    vector< pair<long long, long long> > E1(m1);
    for (auto &[x, y] : E1) scanf("%lld%lld", &y, &x);
    sort(E1.begin(), E1.end());
    long long lst = n % P;
    for (int i = 0; i < m1; ++i) {
        ta.push_back(E1[i].first);
        D.back().push_back(E1[i].second);
        long long now = calcCC(n, D.back());
        D.push_back(D.back());
        res = (res + (lst - now) % P * E1[i].first) % P;
        lst = now;
    }
    E2.resize(m2);
    vector<long long> pnt;
    for (auto &[x, y, z] : E2) {
        scanf("%lld%lld%lld", &y, &z, &x);
        pnt.push_back(y), pnt.push_back(z);
    }
    simpl(pnt);
    solve(0, m1 - 1, split(m1 - 1, pnt));
    auto getId = [&](long long x) {
        return lower_bound(pnt.begin(), pnt.end(), x) - pnt.begin();
    };
    sort(E2.begin(), E2.end());
    vector<int> fa(pnt.size());
    iota(fa.begin(), fa.end(), 0);
    auto find = [&](auto self, int x) -> int {
        return fa[x] == x ? x : self(self, fa[x]);
    };
    for (auto [x, y, z] : E2) {
        y = find(find, getId(y)), z = find(find, getId(z));
        if (y != z) res += x, fa[y] = z;
    }
    printf("%lld\n", (res % P + P) % P);
    return 0;
}