#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_map>
#define MAXN 101010
using namespace std;
typedef long long ll;
int N, M, Q;
int parent[20][MAXN];
int depth[MAXN];
int in[MAXN], out[MAXN];
int max_height;
int dfs_ordering[MAXN];
vector<int> adj[MAXN];
typedef struct save_points {
ll s, e, val;
bool operator < (const save_points& right) {
return val < right.val;
}
} save_points;
typedef struct Query {
ll s, t, x, y;
} Query;
vector<save_points> SP;
vector<Query> queries;
int l[MAXN], r[MAXN];
vector< pair<int, int> > roads;
void fastIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void input() {
cin >> N >> M >> Q;
roads.resize(N);
for (int i = 1; i <= N - 1; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
roads[i] = { min(a, b), max(a, b) };
}
for (int i = 1; i <= M; i++) {
int a, b;
cin >> a >> b;
save_points tmp = { roads[a].first, roads[a].second, b };
SP.push_back(tmp);
}
sort(SP.begin(), SP.end());
queries.resize(Q);
for (int i = 0; i < Q; i++)
cin >> queries[i].s >> queries[i].t >> queries[i].x >> queries[i].y;
}
int Euler_tour_idx, ordering_idx;
void Euler_tour(int n, int dep) { // set in, out, depth, parent
dfs_ordering[n] = ++ordering_idx;
in[n] = ++Euler_tour_idx;
depth[n] = dep;
for (int i = 0; i < adj[n].size(); i++) {
int next = adj[n][i];
if (in[next]) continue;
parent[0][next] = n;
Euler_tour(next, dep + 1);
}
++Euler_tour_idx;
out[n] = Euler_tour_idx;
}
void set_parent() { // for faster lca
int tmp = N, cnt = 0;
while (tmp > 1) {
tmp >>= 1;
cnt++;
}
max_height = cnt;
for (int k = 1; k <= max_height; k++)
for (int i = 2; i <= N; i++)
if (parent[k - 1][i])
parent[k][i] = parent[k - 1][parent[k - 1][i]];
}
int LCA(int a, int b) { // returns lca of node a and b
if (depth[a] != depth[b]) {
if (depth[a] < depth[b]) swap(a, b); // a is deeper
ll dif = depth[a] - depth[b];
for (ll i = 0; dif > 0; i++) {
if (dif & 1) a = parent[i][a];
dif >>= 1;
}
}
if (a != b) {
for (int k = max_height; 0 <= k; k--) {
if (parent[k][a] != 0 && parent[k][a] != parent[k][b]) {
a = parent[k][a];
b = parent[k][b];
}
}
a = parent[0][a];
}
return a;
}
ll tree1[8 * MAXN], tree2[8 * MAXN], tree3[8 * MAXN];
void update(ll tree[], ll n, ll s, ll e, ll tgIdx, ll val) {
if (s == e) {
tree[n] += val;
return;
}
ll lch = n * 2, rch = lch + 1, m = (s + e) / 2;
if (tgIdx <= m) update(tree, lch, s, m, tgIdx, val);
else update(tree, rch, m + 1, e, tgIdx, val);
tree[n] = tree[lch] + tree[rch];
}
ll query(ll tree[], ll n, ll s, ll e, ll fs, ll fe) {
if (e < fs || fe < s) return 0;
if (fs <= s && e <= fe) return tree[n];
ll lch = n * 2, rch = lch + 1, m = (s + e) / 2;
ll left = query(tree, lch, s, m, fs, fe);
ll right = query(tree, rch, m + 1, e, fs, fe);
return left + right;
}
void segclear() {
for (ll i = 0; i < 8 * MAXN; i++)
tree1[i] = tree3[i] = 0;
}
vector<ll> g[MAXN];
ll ans[MAXN];
ll totSP[MAXN]{};
ll cnts[MAXN]{};
void solve() {
for (int i = 0; i < MAXN; i++)
ans[i] = -1;
Euler_tour(1, 0); // for setting in, out, par
set_parent(); // for faster LCA(O(logN))
for (int i = 0; i < Q; i++) { // set for PBS
l[i] = -1;
r[i] = M;
}
for (int i = 0; i < M; i++) {
int S = SP[i].s, E = SP[i].e, VAL = SP[i].val;
if (in[E] <= in[S] && in[S] <= out[E]) swap(S, E);
update(tree2, 1, 1, Euler_tour_idx, in[E], 1); // SP 추가
update(tree2, 1, 1, Euler_tour_idx, out[E], -1);
}
for (int j = 0; j < Q; j++) {
int tmp_lca = LCA(queries[j].s, queries[j].t);
ll tmp = query(tree2, 1, 1, Euler_tour_idx, 1, in[queries[j].s]) + query(tree2, 1, 1, Euler_tour_idx, 1, in[queries[j].t]) - 2 * query(tree2, 1, 1, Euler_tour_idx, 1, in[tmp_lca]);
totSP[j] = tmp;
}
while (1) {
for (int i = 0; i < MAXN; i++)
g[i].clear();
segclear();
bool flag = 0;
for (int i = 0; i < Q; i++) {
if (l[i] + 1 == r[i]) continue;
flag = 1; g[l[i] + r[i] >> 1].push_back(i);
}
if (!flag) break;
for (int i = 0; i < M; i++) {
ll S = SP[i].s, E = SP[i].e, VAL = SP[i].val;
if (in[E] <= in[S] && in[S] <= out[E]) swap(S, E);
update(tree1, 1, 1, Euler_tour_idx, in[E], VAL); // SP (은화 가중치) 추가
update(tree1, 1, 1, Euler_tour_idx, out[E], -VAL);
update(tree3, 1, 1, Euler_tour_idx, in[E], 1); // SP (단순 개수) 추가
update(tree3, 1, 1, Euler_tour_idx, out[E], -1);
for (auto j : g[i]) {
ll tmp_lca = LCA(queries[j].s, queries[j].t);
ll tmp = query(tree1, 1, 1, Euler_tour_idx, 1, in[queries[j].s]) + query(tree1, 1, 1, Euler_tour_idx, 1, in[queries[j].t]) - 2 * query(tree1, 1, 1, Euler_tour_idx, 1, in[tmp_lca]);
ll tmp3 = query(tree3, 1, 1, Euler_tour_idx, 1, in[queries[j].s]) + query(tree3, 1, 1, Euler_tour_idx, 1, in[queries[j].t]) - 2 * query(tree3, 1, 1, Euler_tour_idx, 1, in[tmp_lca]);
if (tmp <= queries[j].y) {
ans[j] = max(ans[j], queries[j].x - totSP[j] + tmp3);
l[j] = i;
}
else r[j] = i;
}
}
}
}
void output() {
for (int i = 0; i < Q; i++) {
if (ans[i] == -1 && queries[i].x >= totSP[i])
ans[i] = queries[i].x - totSP[i];
cout << ans[i] << '\n';
}
}
int main() {
fastIO();
input();
solve();
output();
return 0;
}
