#include <bits/stdc++.h>
using namespace std;
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1};
#define OVL(x,s) for(auto y:x) cout<<y<<s; cout<<"\n";
#ifdef IOI
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__);
#else
#define dbg(...) 1337;
#endif
#define endl "\n"
#define pb push_back
#define F first
#define S second
#define ll long long
#define mod 1000000007
#define all(v) v.begin(),v.end()
#define int long long
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,bmi,bmi2,popcnt,lzcnt")
const int MAXN=1e5+100;
const int BQ=316;
constexpr int logn = 20;
constexpr int maxn = 1 << logn;
uint64_t hilbertorder(uint64_t x, uint64_t y) {
const uint64_t logn = __lg(max(x, y) * 2 + 1) | 1;
const uint64_t maxn = (1ull << logn) - 1;
uint64_t res = 0;
for (uint64_t s = 1ull << (logn - 1); s; s >>= 1) {
bool rx = x & s, ry = y & s;
res = (res << 2) | (rx ? ry ? 2 : 1 : ry ? 3 : 0);
if (!rx) {
if (ry) x ^= maxn, y ^= maxn;
swap(x, y);
}
}
return res;
}
struct Query {
int l, r, id,x,y;
int64_t ord;
inline void calcOrder() {
ord = hilbertorder(l, r);
}
};
inline bool operator<(const Query &a, const Query &b) {
if(a.l / BQ != b.l / BQ)
return a.l < b.l;
return (a.l / BQ )% 2 ? a.r < b.r : a.r > b.r;
}
vector<int> c[MAXN];
vector<Query> queries;
unordered_map<int,int> f,g;
set<int> cc;
int arr[BQ+10];
int arr2[MAXN];
int cnt=0;
int cnt1[BQ+10];
void add(int x){
cnt++;
arr[f[x]/BQ+1]+=x;
cnt1[f[x]/BQ+1]++;
arr2[f[x]]++;
}
void remove(int x){
cnt--;
arr[f[x]/BQ+1]-=x;
cnt1[f[x]/BQ+1]--;
arr2[f[x]]--;
}
vector<pair<int,int>> v[MAXN];
void a(int a,int b){
int x=-1;
for(auto y:v[a]){
if(y.F==b){
x=y.S;
break;
}
}
if(x==-1) return;
for(auto y:c[x]){
add(y);
}
}
void re(int a,int b){
int x=-1;
for(auto y:v[a]){
if(y.F==b){
x=y.S;
break;
}
}
if(x==-1) return;
for(auto y:c[x]) remove(y);
}
const int MOD = 1e9 + 7;
const int BUF_SZ = 1 << 15;
inline namespace Input {
char buf[BUF_SZ];
int pos;
int len;
char next_char() {
if (pos == len) {
pos = 0;
len = (int)fread(buf, 1, BUF_SZ, stdin);
if (!len) { return EOF; }
}
return buf[pos++];
}
int read_int() {
int x;
char ch;
int sgn = 1;
while (!isdigit(ch = next_char())) {
if (ch == '-') { sgn *= -1; }
}
x = ch - '0';
while (isdigit(ch = next_char())) { x = x * 10 + (ch - '0'); }
return x * sgn;
}
}
int ans[MAXN];
signed main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
int n,m,q;
// cin>>n>>m>>q;
n=read_int();
m=read_int();
q=read_int();
for(int i=1;i<n;i++){
int a,b;
a=read_int();
b=read_int();
// cin>>a>>b;
v[a].pb({b,i});
v[b].pb({a,i});
}
for(int i=0;i<m;i++){
int t;
t=read_int();
// cin>>t;
int d;
d=read_int();
// cin>>d;
cc.insert(d);
c[t].pb(d);
}
int comp=1;
for(auto x:cc){
f[x]=comp;
g[comp]=x;
comp++;
}
for(int i=0;i<q;i++){
int l,r,x,y;
// cin>>l>>r>>x>>y;
l=read_int();
r=read_int();
x=read_int();
y=read_int();
if(l>r) swap(l,r);
queries.pb({.l=l,.r=r,.id=i,.x=x,.y=y});
}
sort(all(queries));
int l=0;
int r=0;
for(int i=0;i<q;i++){
int ql=queries[i].l;
int qr=queries[i].r;
int id=queries[i].id;
int x=queries[i].x;
int y=queries[i].y;
while(r<qr){
a(r,r+1);
r++;
}
while(l>ql){
a(l,l-1);
l--;
}
while(l<ql){
re(l,l+1);
l++;
}
while(r>qr){
re(r,r-1);
r--;
}
int t=0;
int k=cnt;
for(int i=1;i<=BQ;i++){
if(y>=arr[i]){
y-=arr[i];
t=i;
k-=cnt1[i];
}else break;
}
for(int i=BQ*(t);i<BQ*(t+1);i++){
if(!g.count(i)) continue;
int c=arr2[i];
int x=g[i];
k-=min((y/x),c);
y-=min(y/x,c)*x;
}
if(x>=k){
ans[id]=x-k;
}else ans[id]=-1;
}
for(int i=0;i<q;i++) cout<<ans[i]<<"\n";
}
