#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 1e5 + 25;
#define mid ((l + r) >> 1)
#define tl (node + 1)
#define tr (node + 2 * (mid - l + 1))
struct SegmentTree {
ll tree[MAXN << 1];
void init () {
for (int i = 1; i < 2 * MAXN; i++) tree[i] = 0;
}
void update (int l, int r, int a, int b, int c, int node) {
if (l > b || r < a) return;
if (l >= a && r <= b) {
tree[node] += c;
return;
}
update(l, mid, a, b, c, tl); update(mid + 1, r, a, b, c, tr);
}
ll get (int l, int r, int a, int node) {
if (l == r) return tree[node];
if (a <= mid) return tree[node] + get(l, mid, a, tl);
return tree[node] + get(mid + 1, r, a, tr);
}
} cur, cur3;
vector <int> adj[MAXN];
int n, m, q;
pair <ll, ll> dd[MAXN];
array <ll, 5> queries[MAXN];
ll ans[MAXN];
ll low[MAXN], high[MAXN];
int dep[MAXN], dp[18][MAXN];
void calc (int pos, int par) {
dp[0][pos] = par;
for (auto j : adj[pos]) {
if (j != par) {
dep[j] = 1 + dep[pos];
calc(j, pos);
}
}
}
int jump (int a, int b) {
for (int i = 17; i >= 0; i--) if (b & (1 << i)) a = dp[i][a];
return a;
}
int lca (int a, int b) {
if (dep[a] > dep[b]) swap(a, b);
b = jump(b, dep[b] - dep[a]);
if (a == b) return a;
for (int i = 17; i >= 0; i--) {
int x = dp[i][a], y = dp[i][b];
if (x && y && x != y) {
a = x, b = y;
}
}
return dp[0][a];
}
pair <int, int> edges[MAXN];
ll cur2[MAXN], cur4[MAXN], init[MAXN], finn[MAXN];
vector <pair <ll, ll>> updates[MAXN];
vector <array <ll, 4>> updates2[MAXN];
void dfs (int pos, int par) {
for (auto j : updates[pos]) {
cur.update(1, m, j.first, m, j.second, 1);
cur3.update(1, m, j.first, m, 1, 1);
}
for (auto j : updates2[pos]) {
ll z = cur.get(1, m, j[1], 1);
ll z2 = cur3.get(1, m, j[1], 1);
if (j[2]) {
cur2[j[0]] += z; cur4[j[0]] += z2;
} else {
cur2[j[0]] -= z; cur4[j[0]] -= z2;
}
}
for (auto j : adj[pos]) {
if (j != par) {
dfs(j, pos);
}
}
for (auto j : updates[pos]) {
cur.update(1, m, j.first, m, -j.second, 1);
cur3.update(1, m, j.first, m, -1, 1);
}
}
int main () {
ios::sync_with_stdio(0); cin.tie(0);
cin >> n >> m >> q;
for (int i = 1; i < n; i++) {
int x, y; cin >> x >> y;
adj[x].push_back(y);
adj[y].push_back(x);
edges[i] = {x, y};
}
calc(1, 0);
for (int i = 1; i < 18; i++) {
for (int j = 1; j <= n; j++) {
dp[i][j] = dp[i - 1][dp[i - 1][j]];
}
}
for (int i = 1; i < n; i++) {
if (dep[edges[i].first] < dep[edges[i].second]) {
swap(edges[i].first, edges[i].second);
}
}
for (int i = 1; i <= m; i++) {
ll x, y; cin >> x >> y;
dd[i] = {x, y};
}
sort(dd + 1, dd + m + 1, [&] (pair <int, int> x, pair <int, int> y) {
return x.second < y.second;
});
for (int i = 1; i <= m; i++) {
updates[edges[dd[i].first].first].push_back({i, dd[i].second});
}
for (int i = 1; i <= q; i++) {
ll w, x, y, z; cin >> w >> x >> y >> z;
queries[i] = {w, x, lca(w, x), z, y};
}
for (int i = 1; i <= q; i++) {
low[i] = 1, high[i] = m, ans[i] = 0;
}
{
cur.init(); cur3.init();
for (int i = 1; i <= n; i++) {
updates2[i].clear();
}
for (int i = 1; i <= q; i++) {
cur2[i] = 0; cur4[i] = 0;
updates2[queries[i][2]].push_back({i, m, 0});
updates2[queries[i][2]].push_back({i, m, 0});
updates2[queries[i][0]].push_back({i, m, 1});
updates2[queries[i][1]].push_back({i, m, 1});
}
dfs(1, -1);
for (int i = 1; i <= q; i++) {
init[i] = cur4[i];
}
}
for (int iter = 1; iter <= 18; iter++) {
cur.init(); cur3.init();
for (int i = 1; i <= n; i++) {
updates2[i].clear();
}
for (int i = 1; i <= q; i++) {
if (low[i] > high[i]) continue;
cur2[i] = 0; cur4[i] = 0;
ll mid2 = (low[i] + high[i]) / 2;
updates2[queries[i][2]].push_back({i, mid2, 0});
updates2[queries[i][2]].push_back({i, mid2, 0});
updates2[queries[i][0]].push_back({i, mid2, 1});
updates2[queries[i][1]].push_back({i, mid2, 1});
}
dfs(1, -1);
for (int i = 1; i <= q; i++) {
if (low[i] > high[i]) continue;
ll mid2 = (low[i] + high[i]) / 2;
if (cur2[i] <= queries[i][3]) {
low[i] = mid2 + 1; ans[i] = mid2; finn[i] = cur4[i];
} else {
high[i] = mid2 - 1;
}
}
}
for (int i = 1; i <= q; i++) {
//cout << i << ": " << init[i] << " " << finn[i] << '\n';
if (init[i] - finn[i] <= queries[i][4]) {
cout << queries[i][4] - init[i] + finn[i] << '\n';
} else {
cout << "-1\n";
}
}
}
