#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
#define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I)
#define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I)
#define FOA(I, A) for(auto &I : A)
#define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n';
#define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n';
#define printz(A,L,R) FOR(OK, 0, L){FOR(KO, 0, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n';
#define fs first
#define sd second
#define ii pair<int,int>
#define iii pair<int, ii>
#define all(A) A.begin(), A.end()
#define quickly ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define div alksdjf
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const int oo = 1e9;
int n, m, q;
vector<int> g[N];
ii edge[N], sta[N];
vector<int> result[N];
int s[N], t[N], w[N];
int gold[N], silver[N];
struct Segment_tree{
int sg[N << 2];
void reset(){
memset(sg, 0, sizeof sg);
}
void update(int id, int l, int r, int pos, int val){
if(l > pos || r < pos){
return;
}
if(l == r){
sg[id] += val;
return;
}
int mid = (l + r) >> 1;
update(id << 1, l, mid, pos, val);
update(id << 1 | 1, mid + 1, r, pos, val);
sg[id] = sg[id << 1] + sg[id << 1 | 1];
}
int get(int id, int l, int r, int u, int v){
if(l > v || r < u){
return 0;
}
if(u <= l && r <= v){
return sg[id];
}
int mid = (l + r) >> 1;
return get(id << 1, l, mid, u, v) + get(id << 1 | 1, mid + 1, r, u, v);
}
} sg;
struct HeavyLight{
int el;
int nxt[N], top[N], sz[N], parent[N];
int st[N], en[N], h[N];
void DFS(int u, int par){
sz[u] = 1;
FOA(v, g[u]){
if(v == par){
continue;
}
parent[v] = u;
h[v] = h[u] + 1;
DFS(v, u);
sz[u] += sz[v];
if(sz[nxt[u]] < sz[v]){
nxt[u] = v;
}
}
}
void HLD(int u, int par, int tp){
st[u] = ++el;
top[u] = tp;
if(nxt[u]){
HLD(nxt[u], u, tp);
}
FOA(v, g[u]){
if(v == par || v == nxt[u]){
continue;
}
HLD(v, u, v);
}
en[u] = el;
}
int LCA(int u, int v){
while(top[u] != top[v]){
if(h[top[u]] < h[top[v]]){
swap(u, v);
}
u = parent[top[u]];
}
if(h[u] > h[v]) swap(u, v);
return u;
}
int path(int u, int v){
int res = 0;
while(top[u] != top[v]){
if(h[top[u]] < h[top[v]]){
swap(u, v);
}
res += sg.get(1, 1, n, st[top[u]], st[u]);
u = parent[top[u]];
}
if(h[u] > h[v]) swap(u, v);
res += sg.get(1, 1, n, st[u] + 1, st[v]);
return res;
}
} hld;
namespace BinarySearch{
int L[N], R[N], ans[N];
vector<int> query[N];
void working(){
FOR(mid, 1, m){
int u = sta[mid].sd, cost = sta[mid].fs;
sg.update(1, 1, n, hld.st[u], cost);
FOA(i, query[mid]){
int get = hld.path(s[i], t[i]);
if(get <= silver[i]){
L[i] = mid + 1;
ans[i] = mid;
}
else{
R[i] = mid - 1;
}
}
query[mid].clear();
}
}
void solve(){
FOR(i, 1, q){
L[i] = 1, R[i] = m;
}
FOR(times, 1, 20){
sg.reset();
FOR(i, 1, q){
if(L[i] <= R[i]){
query[L[i] + R[i] >> 1].push_back(i);
}
}
working();
}
}
} using namespace BinarySearch;
void AllPath(){
sg.reset();
FOR(i, 1, m){
int u = sta[i].sd;
sg.update(1, 1, n, hld.st[u], 1);
FOA(v, result[i]){
w[v] = hld.path(s[v], t[v]);
}
}
FOR(i, 1, q){
int cost = hld.path(s[i], t[i]);
if(cost - w[i] <= gold[i]){
cout << gold[i] - cost + w[i] << '\n';
}
else{
cout << -1 << '\n';
}
}
}
signed main(){ quickly
cin >> n >> m >> q;
FOR(i, 1, n - 1){
int u, v;
cin >> u >> v;
edge[i] = {u, v};
g[u].push_back(v);
g[v].push_back(u);
}
hld.DFS(1, -1);
hld.HLD(1, -1, 1);
FOR(i, 1, m){
int x, c;
cin >> x >> c;
int u = edge[x].fs, v = edge[x].sd;
if(hld.st[u] > hld.st[v]){
swap(u, v);
}
sta[i] = {c, v};
}
sort(sta + 1, sta + 1 + m);
FOR(i, 1, q){
cin >> s[i] >> t[i] >> gold[i] >> silver[i];
}
solve();
FOR(i, 1, q){
result[ans[i]].push_back(i);
}
AllPath();
}
