#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 998244353;
using Mint = ModInt<MO>;

int root(vector<int> &uf, int u) {
  return (uf[u] < 0) ? u : (uf[u] = root(uf, uf[u]));
}
bool connect(vector<int> &uf, int u, int v) {
  u = root(uf, u);
  v = root(uf, v);
  if (u == v) return false;
  if (uf[u] > uf[v]) swap(u, v);
  uf[u] += uf[v];
  uf[v] = u;
  return true;
}


Int N;
int A, B;
vector<Int> D;
vector<int> X;
vector<Int> U, V;
vector<int> W;

vector<pair<int, int>> es;


namespace brute {
constexpr int F = 19;
vector<int> ufs[F];

// (u, v), (u + 1, v + 1), ..., (u + 2^f-1, v + 2^f-1)
int rec(int f, int u, int v) {
  int ret = 0;
  if (connect(ufs[f], u, v)) {
    if (f) {
      ret += rec(f - 1, u, v);
      ret += rec(f - 1, u + (1 << (f-1)), v + (1 << (f-1)));
    } else {
      ret += 1;
    }
  }
  return ret;
}

Mint run() {
  for (int f = 0; f < F; ++f) {
    ufs[f].assign(N, -1);
  }
  Mint ans = 0;
  for (const auto &e : es) {
    int num = 0;
    if (e.second < A) {
      const int a = e.second;
      const int f = 31 - __builtin_clz(N - D[a]);
      num += rec(f, 0, D[a]);
      num += rec(f, N - D[a] - (1 << f), N - (1 << f));
    } else {
      const int b = e.second - A;
      num += rec(0, U[b], V[b]);
    }
// cerr<<e<<": "<<num<<endl;
    ans += Mint(e.first) * num;
  }
  return ans;
}
}  // brute


namespace fast {
// vertex 0, ..., n-1
struct HugeGraph {
  Int n;
  vector<Int> ds;
  explicit HugeGraph(Int n_ = 0) : n(n_) {}
  // add edges (u, u + d) for 0 <= u < n - d
  void add(Int d) {
    assert(1 <= d); assert(d < n);
    ds.push_back(d);
  }
  // (# of connected components, component representatives for us)
  // reduce ds so that |ds| <= 2 log_2(min ds) + 1, representing the same graph
  pair<Int, vector<Int>> run(vector<Int> us) {
    Int off = 0;
    priority_queue<pair<Int, Int>, vector<pair<Int, Int>>, greater<pair<Int, Int>>> que;
    for (const Int d : ds) que.emplace(d, d);
    ds.clear();
    // reduce the problem to the graph on [0, nn) with d \in que (with offset)
    Int nn = n, c = 0;
    for (; ; ) {
      if (que.empty()) {
        c += nn;
        break;
      }
      const Int d0 = que.top().first + off;
      const Int save0 = que.top().second;
      que.pop();
      if (d0 == 0) {
        continue;
      }
      ds.push_back(save0);
      for (Int &u : us) if (u < nn) u %= d0;
      if (que.empty()) {
        c += d0;
        break;
      }
      const Int d1 = que.top().first + off;
      const Int k = d1 / d0;
      nn -= d0 * k;
      if (nn < d0) c += (d0 - nn);
      off -= d0 * k;
      if (d0 < nn) que.emplace(d0 - off, save0);
    }
    return make_pair(c, us);
  }
};

Mint run() {
  vector<int> as;
  for (const auto &e : es) if (e.second < A) {
    as.push_back(e.second);
  }
  
  // MST with A-edge
  Mint ans = 0;
  {
    Int numComps = N;
    HugeGraph hg(N);
    for (const int a : as) {
      hg.add(D[a]);
      const Int res = hg.run({}).first;
      ans += Mint(X[a]) * (numComps - res);
      numComps = res;
    }
  }
  
  // TODO: virtual tree
  
  return ans;
}
}  // fast


int main() {
  for (; ~scanf("%lld%d%d", &N, &A, &B); ) {
    D.resize(A);
    X.resize(A);
    for (int a = 0; a < A; ++a) {
      scanf("%lld%d", &D[a], &X[a]);
    }
    U.resize(B);
    V.resize(B);
    W.resize(B);
    for (int b = 0; b < B; ++b) {
      scanf("%lld%lld%d", &U[b], &V[b], &W[b]);
    }
    
    es.resize(A + B);
    for (int a = 0; a < A; ++a) {
      es[a] = make_pair(X[a], a);
    }
    for (int b = 0; b < B; ++b) {
      es[A + b] = make_pair(W[b], A + b);
    }
    sort(es.begin(), es.end());
    
cerr<<"N = "<<N<<", A = "<<A<<", B = "<<B<<endl;
// cerr<<"es = "<<es<<endl;
    
    const Mint ans = fast::run();
    printf("%u\n", ans.x);
#ifdef LOCAL
if(N<=200'000){
 const Mint brt=brute::run();
 if(brt!=ans)cerr<<"brt = "<<brt<<endl;
if(B==0)
 assert(brt==ans);
}
#endif
  }
  return 0;
}