#include<bits/stdc++.h>
using namespace std;
#define int int64_t
#define pb push_back
using pii=pair<int,int>;
const int lim=2e5+100;
struct{
int tree[lim];
void update(int p,int val){
while(p<lim){
tree[p]+=val;
p+=p&-p;
}
}
void init(){
for(int i=0;i<lim;i++){
tree[i]=0;
}
}
int query(int p){
int ans=0;
while(p){
ans+=tree[p];
p-=p&-p;
}
return ans;
}
int query(int l,int r){
if(r<l)return 0;
return query(r)-query(l-1);
}
}fw1,fw2;
vector<int>v[lim];
int tin[lim],tt=1;
int sz[lim],par[lim],head[lim];
int sbs(int node){
for(int i=0;i<v[node].size();i++){
if(v[node][i]==par[node]){
swap(v[node][i],v[node].back());
v[node].pop_back();
break;
}
}
sz[node]=1;
for(int j:v[node]){
par[j]=node;
sz[node]+=sbs(j);
}
return sz[node];
}
void build(int node){
tin[node]=tt++;
if(!head[node])head[node]=node;
if(!v[node].size())return;
int heavy=v[node][0];
for(int j:v[node]){
if(sz[heavy]<sz[j]){
heavy=j;
}
}
head[heavy]=head[node];
build(heavy);
for(int j:v[node]){
if(j==heavy)continue;
build(j);
}
}
pii query(int x,int y){
int ans1=0,ans2=0;
while(1){
if(tin[y]<tin[x])swap(x,y);
if(head[x]==head[y]){
ans1+=fw1.query(tin[x]+1,tin[y]);
ans2+=fw2.query(tin[x]+1,tin[y]);
break;
}
ans1+=fw1.query(tin[head[y]],tin[y]);
ans2+=fw2.query(tin[head[y]],tin[y]);
y=par[head[y]];
}
return {ans1,ans2};
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int n,m,q;
cin>>n>>m>>q;
pii edges[n-1];
for(int i=0;i<n-1;i++){
int x,y;
cin>>x>>y;
edges[i]={x,y};
v[x].pb(y);
v[y].pb(x);
}
pii guys[m];
for(int i=0;i<m;i++){
cin>>guys[i].second>>guys[i].first;
guys[i].second--;
}
sort(guys,guys+m);
sbs(1);
build(1);
for(int i=0;i<n-1;i++){
if(edges[i].first!=par[edges[i].second])swap(edges[i].first,edges[i].second);
}
for(int i=0;i<m;i++){
guys[i].second=edges[guys[i].second].second;
}
int a[q],b[q],c[q],d[q];
for(int i=0;i<q;i++){
cin>>a[i]>>b[i]>>c[i]>>d[i];
}
vector<int>mids[m+1];
int l[q],r[q],ans[q];
for(int i=0;i<q;i++){
l[i]=0,r[i]=m;
ans[i]=-1;
mids[m>>1].pb(i);
}
for(int i=0;i<17;i++){
fw1.init();
fw2.init();
for(int mid=0;mid<m;mid++){
fw1.update(tin[guys[mid].second],1);
}
for(int mid=0;mid<=m;mid++){
for(int j:mids[mid]){
auto[ans1,ans2]=query(a[j],b[j]);
if(ans1<=c[j]&&ans2<=d[j]){
ans[j]=c[j]-ans1;
l[j]=mid+1;
if(l[j]<=r[j])mids[(l[j]+r[j])>>1].pb(j);
}else if(ans1<=c[j]){
r[j]=mid-1;
if(l[j]<=r[j])mids[(l[j]+r[j])>>1].pb(j);
}else if(ans2<=d[j]){
l[j]=mid+1;
if(l[j]<=r[j])mids[(l[j]+r[j])>>1].pb(j);
}
}
mids[mid].clear();
if(mid!=m){
fw1.update(tin[guys[mid].second],-1);
fw2.update(tin[guys[mid].second],guys[mid].first);
}
}
}
for(int j:ans)cout<<j<<'\n';
}
