#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
using namespace std;
const int maxn = 1e5 + 5;
const int mod = 1e9 + 7;
const int oo = 1e18;
const int logg = 21;
int n, m, q;
vector<int> adj[maxn];
pair<int, int> E[maxn];
pair<int, int> Q[maxn];
// prepare PBS
int L[maxn], R[maxn], ans[maxn];
vector<int> bucket[maxn];
// Query
int S[maxn], T[maxn], X[maxn], Y[maxn];
// build tree BIT
struct Fenwick{
int bit[maxn];
void FILL(void){
memset(bit, 0, sizeof bit);
}
void update(int pos, int val){
for(; pos <= n; pos += pos & (-pos)) bit[pos] += val;
}
int get(int pos){
int ans = 0;
for(; pos > 0; pos -= pos & (-pos)) ans += bit[pos];
return ans;
}
} BIT1, BIT2;
// build LCA
int par[maxn][logg], depth[maxn], tin[maxn], tout[maxn];
void dfs(int u, int pa){
tin[u] = ++tin[0];
for(int v : adj[u]){
if(v == pa) continue;
depth[v] = depth[u] + 1;
par[v][0] = u;
dfs(v, u);
}
tout[u] = tin[0];
}
int LCA(int u, int v){
if(depth[u] < depth[v]) swap(u, v);
for(int j = logg - 1; j >= 0; j--){
if(depth[par[u][j]] >= depth[v]) u = par[u][j];
}
if(u == v) return u;
for(int j = logg - 1; j >= 0; j--){
if(par[u][j] != par[v][j]){
u = par[u][j];
v = par[v][j];
}
}
return par[u][0];
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
//freopen ("tree.inp" , "r" ,stdin);
//freopen ("tree.out" , "w" ,stdout);
cin >> n >> m >> q;
for(int i = 1; i < n; i++){
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
E[i] = {u, v};
}
par[1][0] = 1;
dfs(1, 0);
for(int j = 1; j < logg; j++){
for(int i = 1; i <= n; i++){
par[i][j] = par[par[i][j - 1]][j - 1];
}
}
for(int i = 1; i < n; i++){
if(LCA(E[i].first, E[i].second) == E[i].second) swap(E[i].first, E[i].second);
}
for(int i = 1; i <= m; i++){
cin >> Q[i].first >> Q[i].second;
swap(Q[i].first, Q[i].second);
}
sort(Q + 1, Q + m + 1);
for(int i = 1; i <= q; i++){
cin >> S[i] >> T[i] >> X[i] >> Y[i];
L[i] = 0;
R[i] = m;
}
bool process = true;
while(process){
for(int i = 0; i <= m; i++) bucket[i].clear();
BIT1.FILL();
BIT2.FILL();
process = false;
for(int i = 1; i <= q; i++){
if(L[i] <= R[i]){
int mid = (L[i] + R[i]) / 2;
bucket[mid].push_back(i);
process = true;
}
}
if(!process) break;
for(int i = 1; i <= m; i++){
int u = E[Q[i].second].second;
BIT1.update(tin[u], 1);
BIT1.update(tout[u] + 1, - 1);
}
for(int i = 0; i <= m; i++){
if(i > 0){
int u = E[Q[i].second].second;
BIT1.update(tin[u], -1);
BIT1.update(tout[u] + 1, 1);
BIT2.update(tin[u], Q[i].first);
BIT2.update(tout[u] + 1, -Q[i].first);
}
for(int id : bucket[i]){
int total = BIT2.get(tin[S[id]]) + BIT2.get(tin[T[id]]) - 2 * BIT2.get(tin[LCA(S[id], T[id])]);
if(total <= Y[id]){
ans[id] = BIT1.get(tin[S[id]]) + BIT1.get(tin[T[id]]) - 2 * BIT1.get(tin[LCA(S[id], T[id])]);
L[id] = i + 1;
}
else R[id] = i - 1;
}
}
}
for(int i = 1; i <= q; i++){
cout << max(-1LL, X[i] - ans[i]) << '\n';
}
return 0;
}
