#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,popcnt,lzcnt")
using namespace std;
using ll = long long; using pii = pair<ll,ll>;
const ll Nm = 262144; const ll E = 18; const ll INF = 2e18;
struct Node {
map<ll,ll> m0; //{cost -> #}
//map<ll,pii> mps; //{aggregate cost, aggregate # at val}
vector<array<ll,3>> mps;
ll cptot = 0;
void prc() {
//mps[-INF]={0,0};
mps.push_back({-INF,0,0});
ll nc = 0; ll vc = 0;
for (pii p0: m0) {
ll n1 = p0.second; ll c1 = p0.first;
nc += n1; vc += n1*c1;
//mps[c1]={vc,nc};
mps.push_back({c1,vc,nc});
}
}
Node(){}
Node(vector<ll> v1) {
for (ll x: v1) {
if (x>0) {
m0[x]++;
cptot++;
} else {
m0[-x]--;
cptot--;
}
}
prc();
}
Node(Node n1, Node n2) {
for (pii p0: n1.m0) {
m0[p0.first]+=p0.second;
}
for (pii p0: n2.m0) {
m0[p0.first]+=p0.second;
}
cptot = n1.cptot+n2.cptot;
prc();
}
pii qry(ll x) {
auto A0 = *(--upper_bound(mps.begin(),mps.end(),(array<ll,3>){x,INF,INF}));
return (pii){A0[1],A0[2]};
//return {(*A0).second;
}
};
inline ll v2(ll x) {
return __builtin_ctz(x);
}
inline ll l2(ll x) {
return (31-__builtin_clz(x));
}
inline pii fz(pii p1, pii p2) {
return ((p1.second<p2.second) ? p1 : p2);
}
vector<ll> floc(Nm,INF); //first location
vector<ll> lloc(Nm,-INF); //last location
vector<pii> adj[Nm];
ll radj[Nm];
ll ht[Nm];
ll locr[Nm]; //road location: index of bottom node
Node st[2*Nm]; //euler tour segtree
vector<ll> ppe[Nm]; //preprocess edges
pii ett[Nm][E+1];
pii ginf(vector<ll>& v1, ll x) {
ll a1=0,b1=0;
for (auto A0: v1) {
pii c1 = st[A0].qry(x);
a1 += c1.first; b1 += c1.second;
}
return {a1,b1}; //{cost <=val, # <=val}
}
ll nv(vector<ll> v1, ll ctot) {
ll cmin = 0; ll cmax = 2e9;
//binary search for largest c for which
//ginf(c).first<=ctot
while (cmin != cmax) {
ll ctest = (cmin+cmax+1)/2;
if (ginf(v1,ctest).first<=ctot) {
cmin = ctest;
} else {
cmax = ctest-1;
}
}
pii gf0 = ginf(v1,cmin);
pii gf1 = ginf(v1,cmin+1);
if (gf0.second==gf1.second || gf0.first==ctot) {
return gf0.second;
} else {
return (gf0.second+(ctot-gf0.first)/(cmin+1));
}
}
ll lca(ll x, ll y) {
x = floc[x]; y = floc[y];
if (x>y) {
swap(x,y);
}
ll lx = l2(y-x+1);
return fz(ett[x][lx],ett[y-(1<<lx)+1][lx]).first;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
ll N,M,Q; cin >> N >> M >> Q;
for (ll i=0;i<(N-1);i++) {
ll a,b; cin >> a >> b; a--; b--;
adj[a].push_back({b,i});
adj[b].push_back({a,i});
}
vector<ll> ettv;
stack<pii> st0; //euler tour
st0.push({0,0});
radj[0]=-1;
ht[0]=0;
while (!st0.empty()) {
pii p0 = st0.top(); st0.pop();
ll x = p0.first; ll t = p0.second;
ettv.push_back(x);
if (t==0) {
for (pii p1: adj[x]) {
ll y = p1.first; ll i = p1.second;
if (y==radj[x]) {
continue;
}
radj[y]=x;
ht[y]=1+ht[x];
locr[i]=y;
st0.push({x,1});
st0.push({y,0});
}
}
}
assert(ettv.size()<=Nm);
for (ll i=0;i<ettv.size();i++) {
//cout << "ettv: "<<ettv[i]<<"\n";
floc[ettv[i]]=min(floc[ettv[i]],i);
lloc[ettv[i]]=max(lloc[ettv[i]],i);
ett[i][0]={ettv[i],ht[ettv[i]]};
}
for (ll e=1;e<=E;e++) {
for (ll i=0;i<=(Nm-(1<<e));i++) {
ett[i][e]=fz(ett[i][e-1],ett[i+(1<<(e-1))][e-1]);
}
}
for (ll m=0;m<M;m++) {
ll p,c; cin >> p >> c;
p--;
ppe[floc[locr[p]]-1].push_back(c);
ppe[lloc[locr[p]]].push_back(-c);
}
for (ll i=0;i<Nm;i++) {
st[i+Nm]=Node(ppe[i]);
}
// for (ll i=0;i<ettv.size();i++) {
// cout << "i="<<i<<"\n";
// cout << "ettv: "<<ettv[i]<<"\n";
// cout << "ppe elem:\n";
// for (ll x: ppe[i]) {
// cout << x<<"\n";
// }
// }
for (ll i=(Nm-1);i>=1;i--) {
st[i]=Node(st[2*i],st[2*i+1]);
}
for (ll q=0;q<Q;q++) {
ll s,t,x,y; cin >> s >> t >> x >> y;
s--; t--;
ll lc = lca(s,t);
ll ntot = 0;
vector<ll> vqry;
ll a = floc[lc]; ll b = floc[s]-1;
//cout << "s,t,lc="<<s<<","<<t<<","<<lc<<"\n";
//cout << "a,b="<<a<<","<<b<<"\n";
while (a<=b) {
ll va = v2(a); ll vb = v2(b+1);
if (va<vb) {
ll p = (a>>va)+(1<<(E-va));
//cout << "p="<<p<<", cp="<<st[p].cptot<<"\n";
ntot += st[p].cptot;
vqry.push_back(p);
a += (1<<va);
} else {
ll p = (b>>vb)+(1<<(E-vb));
//cout << "p="<<p<<", cp="<<st[p].cptot<<"\n";
ntot += st[p].cptot;
vqry.push_back(p);
b -= (1<<vb);
}
}
a = floc[lc]; b = floc[t]-1;
//cout << "a,b="<<a<<","<<b<<"\n";
while (a<=b) {
ll va = v2(a); ll vb = v2(b+1);
if (va<vb) {
ll p = (a>>va)+(1<<(E-va));
//cout << "p="<<p<<", cp="<<st[p].cptot<<"\n";
ntot += st[p].cptot;
vqry.push_back(p);
a += (1<<va);
} else {
ll p = (b>>vb)+(1<<(E-vb));
//cout << "p="<<p<<", cp="<<st[p].cptot<<"\n";
ntot += st[p].cptot;
vqry.push_back(p);
b -= (1<<vb);
}
}
ll utot = nv(vqry,y);
//cout << "utot="<<utot<<"\n";
if ((x+utot)<ntot) {
cout << "-1\n";
} else {
cout << (x+utot-ntot)<<"\n";
}
}
}
//0 2 0 1 4 1 3 1 0
// 0
//1 2
//ett: 01020
//edges: (01) (10) (02) (20)
