#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) (x).begin(), (x).end()
template<template<typename> class Container, typename G>
ostream& operator<<(ostream& os, Container<G> x) {
int f = 0; os << '{'; for (auto &i: x) os << (f++ ? ", " : ""), os << i; os << "}";
return os;
}
void _print() {cerr << "]\n";}
template<typename T, typename... V>
void _print(T t, V... v) {cerr << t; if (sizeof...(v)) cerr <<", "; _print(v...);}
#ifdef DEBUG
#define dbg(x...) cerr << "\e[91m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[39m" << endl;
#else
#define dbg(x...)
#endif
#define pii pair<int, int>
#define f first
#define s second
namespace ds{
const int n=100005;
const int SQ=300;
int cnt[(n/SQ)+5],sm[(n/SQ)+5],cn[n],smm[n];
vector<int>c;unordered_map<int,int>comp;
void init(){
sort(all(c));
c.resize(unique(all(c))-c.begin());
for(int i=0;i<c.size();i++){
comp[c[i]]=i;
}
}
int query(int v){
//given that we can use up to v silvers, returns how many things are leftover
dbg(v);
int cur=0,pos=0,c=0;
for(int i=0;i<n/SQ and pos<ds::c.size();i++){
if(cur+sm[i]<=v){
cur+=sm[i];
c+=cnt[i];
pos+=SQ;
}else{
break;
}
}
for(int i=0;i<SQ and pos<ds::c.size();i++){
if(cur+smm[pos]<=v){
cur+=smm[pos];
c+=(cn[pos]);
pos++;
}else{
break;
}
}
dbg("HI",v,cur,ds::c[pos],pos);
while(pos<ds::c.size() and cur+ds::c[pos]<=v){
cur+=ds::c[pos];
c++;
}
return c;
}
void add(int v){
int real=c[v];
//dbg("ADD",real);
int bucket=v/SQ;
smm[v]+=real;
cn[v]++;
sm[bucket]+=real;
cnt[bucket]++;
}
void remove(int v){
int real=c[v];
//dbg("REM",real);
int bucket=v/SQ;
smm[v]-=real;
cn[v]--;
sm[bucket]-=real;
cnt[bucket]--;
}
}
vector<int>adj[100005];
pii e[100005];
vector<int> things[100005];
int depth[100005],tin[100005],tbitin[100005],tmid[100005],tout[100005],w[100005];
vector<int>v;
void d(int u,int p=-1){for(int i:adj[u]){if(i==p)continue;depth[i]=depth[u]+1;d(i,u);}}
int jmp[100006][20],ts[100005],pmo[100005];
int counter=0;
void dfs(int u,int p=-1){
ts[u]=counter++;
jmp[u][0]=p;
for(int i=1;i<20;i++){
if(jmp[u][i-1]!=-1){
jmp[u][i]=jmp[jmp[u][i-1]][i-1];
}
}
tin[u]=v.size();
dbg(u,things[u],adj[u]);
for(auto i:things[u]){ v.push_back(i); }
tbitin[u]=v.size();
for(int i:adj[u]){
if(i==p)continue;
depth[i]=depth[u]+1;
dfs(i,u);
}
tmid[u]=v.size();
for(auto i:things[u]){ v.push_back(i); }
tout[u]=v.size();
pmo[u]=counter++;
}
bool is_anc(int a,int b){
return ts[a]<=ts[b] and pmo[b]<=pmo[a];
}
int lca(int a,int b){
if(is_anc(a,b))return a;
if(is_anc(b,a))return b;
return 1;
}
int dist(int u,int v){
return depth[u]+depth[v]-2*depth[lca(u,v)];
}
inline int64_t hilbertOrder(int x, int y, int pow, int rotate) {
if (pow == 0) { return 0; }
int hpow = 1 << (pow-1);
int seg = (x < hpow) ? ( (y < hpow) ? 0 : 3) : ( (y < hpow) ? 1 : 2);
seg = (seg + rotate) & 3;
const int rotateDelta[4] = {3, 0, 0, 1};
int nx = x & (x ^ hpow), ny = y & (y ^ hpow);
int nrot = (rotate + rotateDelta[seg]) & 3;
int64_t subSquareSize = int64_t(1) << (2*pow - 2);
int64_t ans = seg * subSquareSize;
int64_t add = hilbertOrder(nx, ny, pow-1, nrot);
ans += (seg == 1 || seg == 2) ? add : (subSquareSize - add - 1);
return ans;
}
struct query{
int l,r,s,t,x,y,ans,val,inx;
bool operator<(query &other){
return val<other.val;
}
};
query q[100005];
int32_t main(){
int n,m,qq;cin>>n>>m>>qq;
for(int i=0;i<n-1;i++){cin>>e[i].f>>e[i].s;adj[e[i].f].push_back(e[i].s);adj[e[i].s].push_back(e[i].f);}
d(1);
for(int i=0;i<n-1;i++){if(depth[e[i].f]>depth[e[i].s])swap(e[i].f,e[i].s);}
for(int i=0;i<m;i++){int p,v;cin>>p>>v;p--;things[e[p].s].push_back(i);::w[i]=v;dbg(e[p].s,w[i]);ds::c.push_back(w[i]);}
ds::init();
for(int i=0;i<m;i++)w[i]=ds::comp[w[i]];
for(int i=1;i<=n;i++){
dbg(i,things[i]);
}
dfs(1);
dbg(::v);
dbg(qq);
for(int i=0;i<qq;i++){
dbg(i);
cin>>q[i].s>>q[i].t>>q[i].x>>q[i].y;q[i].inx=i;
//if(tin[q[i].s]>tin[q[i].t])swap(q[i].s,q[i].t);
if(ts[q[i].s]>ts[q[i].t])swap(q[i].s,q[i].t);
// s is higher
//if(tin[q[i].s]<=tin[q[i].t] and tout[q[i].t]<=tout[q[i].s]){
if(is_anc(q[i].s,q[i].t)){
q[i].l=tbitin[q[i].s];q[i].r=tbitin[q[i].t]-1;
}else{
q[i].l=tmid[q[i].s];q[i].r=tbitin[q[i].t]-1;
}
dbg(q[i].s,q[i].t,q[i].l,q[i].r);
q[i].val=hilbertOrder(q[i].l,q[i].r,20,0);
}
sort(q,q+qq);
vector<int>cnt(m);
int l=0,r=0;cnt[v[0]]++;ds::add(w[v[0]]);
//set<int>s;s.insert(v[0]);
int pathlen=1;
function<void(int)>add=[&](int i){
cnt[i]++;
if(cnt[i]==1){ds::add(w[i]);pathlen++;}//s.insert(i);}
if(cnt[i]==2){ds::remove(w[i]);pathlen--;}//s.erase(s.find(i));}
};
function<void(int)>rem=[&](int i){
if(cnt[i]==2){ds::add(w[i]);pathlen++;}//s.insert(i);}
if(cnt[i]==1){ds::remove(w[i]);pathlen--;}//s.erase(s.find(i));}
cnt[i]--;
};
vector<int>ans(qq);
for(int i=0;i<qq;i++){
dbg(i,q[i].l,q[i].r,q[i].s,q[i].t);
while(l>q[i].l){
l--; add(v[l]);
}
while(r<q[i].r){
r++; add(v[r]);
}
while(l<q[i].l){
rem(v[l]);l++;
}
while(r>q[i].r){
rem(v[r]);r--;
}
auto idk=ds::query(q[i].y);//this is min golds needed
//int pathlen=dist(q[i].s,q[i].t);// dist between q[i].s and q[i].t in terms of edges
//int pathlen=s.size();
dbg(pathlen,idk);
q[i].ans=q[i].x-(pathlen-idk);
if(q[i].ans<0)q[i].ans=-1;
ans[q[i].inx]=q[i].ans;
}
for(int i=0;i<qq;i++){
cout<<ans[i]<<"\n";
}
}
