#pragma GCC optimize(2,3,"Ofast","inline","unroll-loops")
#include<bits/stdc++.h>
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define pii pair<ll,ll>
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
bool Mbe;
ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
void write(ll x){
    if(x<0)putchar('-'),x=-x;
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
const ll N=4e5+9,Mod=998244353;
ll n,m1,m2,D[N],X[N],U[N],V[N],W[N],fa[N],ans,rev[N];
vector<vector<ll> >vec[N];
array<ll,2> e[N];
struct DS{
    ll n;
    vector<ll>D;
    DS (ll _n=0): n(_n){}
    void Add(ll x){D.push_back(x);}
    pair<ll,vector<ll> >calc(vector<ll> v){
        priority_queue<pii,vector<pii>,greater<pii> >q;
        for(ll x:D)q.push({x,x});
        vector<ll>().swap(D);
        ll tn=n,cnt=0,lst=n,ofs=0;
        while(1){
            if(q.empty()){
                cnt+=tn;
                break;
            }
            ll d0=q.top().first+ofs,ord=q.top().second;
            q.pop();
            if(!d0)continue;
            D.push_back(ord);
            if(lst>d0){
                lst=d0;
                for(ll &x:v){
                    if(x<tn)x%=d0;
                }
            }
            if(q.empty()){
                cnt+=d0;
                break;
            }
            ll d1=q.top().first+ofs,k=d1/d0;
            tn-=k*d0,ofs-=k*d0;
            if(tn<d0)cnt+=d0-tn;
            if(d0<tn)q.push({d0-ofs,ord});
        }
        return {cnt,v};
    }
};
ll find(ll x){
    if(fa[x]<0)return x;
    return fa[x]=find(fa[x]);
}
bool merge(ll x,ll y){
    x=find(x),y=find(y);
    if(x==y)return 0;
    if(fa[x]>fa[y])swap(x,y);
    fa[x]+=fa[y],fa[y]=x;
    return 1;
}
bool Med;
int main(){
    freopen("mst.in","r",stdin);
    freopen("mst.out","w",stdout);
    cerr<<fabs(&Med-&Mbe)/1048576.0<<"MB\n";
    n=read(),m1=read(),m2=read();
    rep(i,0,m1-1)D[i]=read(),X[i]=read();
    rep(i,0,m2-1)U[i]=read(),V[i]=read(),W[i]=read();
    rep(i,0,m1-1)e[i]={X[i],i};
    rep(i,0,m2-1)e[i+m1]={W[i],i+m1};
    sort(e,e+m1+m2);
    vector<ll>ve;
    rep(i,0,m1+m2-1){
        if(e[i][1]<m1)rev[e[i][1]]=ve.size(),ve.push_back(e[i][1]);
    }
    ll compc=n;
    DS G(n);
    rep(i,0,m1+m2-1){
        if(e[i][1]>=m1)continue;
        G.Add(D[e[i][1]]);
        ll nw=G.calc({}).first;
        ans=(ans+e[i][0]*((compc-nw)%Mod))%Mod;
        compc=nw;
    }
    vector<ll>P;
    rep(i,0,m2-1)P.push_back(U[i]),P.push_back(V[i]);
    sort(P.begin(),P.end());
    P.resize(unique(P.begin(),P.end())-P.begin());
    vector<pair<pii,vector<ll> > >pv;
    if((ll)P.size()>=2){
        vector<ll>init(P.size());
        iota(init.begin(),init.end(),0ll);
        pv.push_back({{0,m1+1},init});
    }
    vector<ll>tr(P.size(),-1);
    while(1){
        bool fl=0;
        vector<vector<pair<pii,vector<ll> > > >tq(m1+1);
        for(pair<pii,vector<ll> >&pseg:pv){
            ll l=pseg.first.first,r=pseg.first.second;
            if(r-l==1)vec[l].push_back(pseg.second);
            else {
                fl=1;
                ll mid=(l+r)>>1;
                tq[mid].push_back(pseg);
            }
        }
        pv.clear();
        if(!fl)break;
        DS G(n);
        rep(i,0,m1){
            if(!tq[i].empty()){
                vector<ll>nfa;
                for(pair<pii,vector<ll> >&vc:tq[i])nfa.insert(nfa.end(),vc.second.begin(),vc.second.end());
                sort(nfa.begin(),nfa.end());
                nfa.resize(unique(nfa.begin(),nfa.end())-nfa.begin());
                vector<ll>tfa(nfa.size());
                rep(j,0,(ll)nfa.size()-1)tfa[j]=P[nfa[j]];
                vector<ll>ret=G.calc(tfa).second;
                rep(j,0,(ll)nfa.size()-1)tr[nfa[j]]=ret[j];
                for(pair<pii,vector<ll> >&vc:tq[i]){
                    ll l=vc.first.first,r=vc.first.second;
                    map<ll,vector<ll> >mp;
                    for(ll&x:vc.second)mp[tr[x]].push_back(x);
                    vector<ll>p;
                    for(pair<ll,vector<ll> >pi:mp){
                        if((ll)pi.second.size()>=2)pv.push_back({{l,i},pi.second});
                        p.push_back(pi.second[0]);
                    }
                    if((ll)p.size()>=2)pv.push_back({{i,r},p});
                }
            }
            if(i==m1)break;
            G.Add(D[ve[i]]);
        }
    }
    rep(i,0,m1-1){
        ll cnt=0;
        for(vector<ll>&v:vec[i])cnt+=((ll)v.size()-1);
        ans=(ans-X[ve[i]]%Mod*cnt%Mod+Mod)%Mod;
    }
    rep(i,0,(ll)P.size())fa[i]=-1;
    rep(i,0,m1+m2-1){
        if(e[i][1]<m1){
            ll cnt=0;
            for(vector<ll>&v:vec[rev[e[i][1]]]){
                rep(j,1,(ll)v.size()-1)cnt+=merge(v[0],v[j]);
            }
            ans=(ans+e[i][0]%Mod*cnt)%Mod;
        }
        else {
            ll x=lower_bound(P.begin(),P.end(),U[e[i][1]-m1])-P.begin();
            ll y=lower_bound(P.begin(),P.end(),V[e[i][1]-m1])-P.begin();
            if(merge(x,y))ans=(ans+e[i][0])%Mod;
        }
    }
    write(ans);
    cerr<<"\n"<<clock()*1.0/CLOCKS_PER_SEC*1000<<"ms\n";
    return 0;
}