#include <bits/stdc++.h>
#define int long long
using namespace std;
int a,b,c;
vector <int> z[1000005];
pair<int,int> t[1000005];
bool cmp(pair<int,int> a ,pair<int,int> b){
return a.second<b.second;
}
int logarit[1000005];
int sta[1000005];
int fin[1000005];
int euler[1000005];
int tour;
int high[1000005];
int st[300001][20];
int sta1[1000005];
int fin1[1000005];
int tour1;
void dfs(int i,int par){
tour++;
sta[i]=tour;
euler[tour]=i;
tour1++;
sta1[i]=tour1;
for (auto p:z[i]){
if (p==par){
continue;
}
high[p]=high[i]+1;
dfs(p,i);
tour++;
euler[tour]=i;
}
tour++;
euler[tour]=i;
fin[i]=tour;
fin1[i]=tour1;
}
void buildst(){
for (int i=1;i<=tour;i++){
st[i][0]=euler[i];
}
for (int j=1;j<=20;j++){
for (int i=1;i+(1<<j)-1<=tour;i++){
int l=st[i][j-1];
int r=st[i+(1<<(j-1))][j-1];
if (high[l]<high[r]){
st[i][j]=l;
}else{
st[i][j]=r;
}
}
}
}
int lca(int x,int y){
int l = min(sta[x], sta[y]);
int r = max(sta[x], sta[y]);
int j = logarit[r - l + 1];
int idx1 = st[l][j];
int idx2 = st[r - (1 << j) + 1][j];
return (high[idx1] < high[idx2] ? idx1 : idx2);
}
struct SegmentTree{
int n;
int tree[4000005];
int lazy[4000005];
void push(int id){
if (lazy[id]!=0){
lazy[id*2]+=lazy[id];
lazy[id*2+1]+=lazy[id];
tree[id*2]+=lazy[id];
tree[id*2+1]+=lazy[id];
lazy[id]=0;
}
}
void build(int id,int l,int r){
lazy[id]=0;
tree[id]=0;
if (l==r){
return;
}
int mid=(l+r)/2;
build(id*2,l,mid);
build(id*2+1,mid+1,r);
}
void update(int id,int l,int r,int x,int y,int val){
if (x>r ||y<l){
return;
}
if (l>=x && y>=r){
tree[id]+=val;
lazy[id]+=val;
return;
}
int mid=(l+r)/2;
push(id);
update(id*2,l,mid,x,y,val);
update(id*2+1,mid+1,r,x,y,val);
tree[id]=tree[id*2]+tree[id*2+1];
}
int get(int id,int l,int r,int pos){
if (l==r){
return tree[id];
}
int mid=(l+r)/2;
push(id);
if (pos<=mid){
return get(id*2,l,mid,pos);
}else{
return get(id*2+1,mid+1,r,pos);
}
}
};
SegmentTree f;
SegmentTree f1;
struct query{
int x,y,g,val;
};
query q[1000005];
vector<int> v[1000005];
int l[1000005];
int r[1000005];
int ans1[1000005];
int ans2[1000005];
pair<int,int> edge[1000005];
int calc(int x,int y){
int idx1=f.get(1,1,tour1,sta1[x]);
int idx2=f.get(1,1,tour1,sta1[y]);
int idx3=2*f.get(1,1,tour1,sta1[lca(x,y)]);
return idx1+idx2-idx3;
}
int calc1(int x,int y){
int idx1=f1.get(1,1,tour1,sta1[x]);
int idx2=f1.get(1,1,tour1,sta1[y]);
int idx3=2*f1.get(1,1,tour1,sta1[lca(x,y)]);
return idx1+idx2-idx3;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> a >> b >> c;
for (int i=1;i<a;i++){
int x,y;
cin >> x >> y;
z[x].push_back(y);
z[y].push_back(x);
edge[i]={x,y};
}
for (int i=1;i<=b;i++){
cin >> t[i].first >> t[i].second;
}
logarit[2] = 1;
for(int i = 3; i <= 1000000; i++){
logarit[i] = logarit[i/2] + 1;
}
sort(t+1,t+1+b,cmp);
dfs(1,0);
buildst();
for (int i=1;i<=c;i++){
cin >> q[i].x >> q[i].y >> q[i].g >> q[i].val;
}
for (int i=1;i<=c;i++){
ans1[i]=0;
ans2[i]=0;
l[i]=0;
r[i]=b;
}
while (true){
bool check=false;
for (int i=1;i<=a;i++){
if (l[i]<=r[i]){
check=true;
int mid=(l[i]+r[i])/2;
v[mid].push_back(i);
}
}
if (!check){
break;
}
f.build(1,1,tour1);
f1.build(1,1,tour1);
for (int i=0;i<=b;i++){
if (i>0){
auto [x,y]=edge[t[i].first];
if (high[x]<high[y]){
swap(x,y);
}
f.update(1,1,tour1,sta1[x],fin1[x],t[i].second);
f1.update(1,1,tour1,sta1[x],fin1[x],1);
}
for (auto p:v[i]){
int precal=calc(q[p].x,q[p].y);
if (q[p].val>=precal){
ans1[p]=i;
l[p]=i+1;
ans2[p]=calc1(q[p].x,q[p].y);
}else{
r[p]=i-1;
}
}
v[i].clear();
}
}
f1.build(1,1,tour1);
for (int i=1;i<=b;i++){
auto [x,y]=edge[t[i].first];
if (high[x]<high[y]){
swap(x,y);
}
// cout << x << " ";
f1.update(1,1,tour1,sta1[x],fin1[x],1);
}
// cout << calc1(3,5) << "\n";
for (int i=1;i<=c;i++){
int val=calc1(q[i].x,q[i].y);
int remain=val-ans2[i];
remain=q[i].g-remain;
if (remain>=0){
cout << remain << "\n";
}else{
cout << -1 << "\n";
}
}
return 0;
}
/*
5 4 1
1 2
1 3
2 4
2 5
2 9
2 4
3 5
4 7
5 3 4 5
*/
/*
5
10 9 3 6 1
3
2 1 2 4
1 2 4
1 2 2
5
2 8 6 4 1
4
3 1 2 9
1 1 3
2 1 4 5
1 2 5
*/
/*
8
01010101
10111000
8
01010101
10111000
10101010
6
110110
011101
001001
8
01010101
11000010
10101010
*/
/*
freopen("test.txt", "r", stdin);
freopen("o2.out", "w", stdout);
*/
