#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt,fma")
#include <bits/stdc++.h>
using namespace std;
const int L = 18;
struct RMQ {
vector<int> val;
array<vector<int>, L> dp;
int min(int i, int j) {
return val[i] < val[j] ? i : j;
}
RMQ(vector<int> a) : val(a) {
for (int i = 0; i < L; i++) {
dp[i].resize(a.size());
}
iota(dp[0].begin(), dp[0].end(), 0);
for (int i = 0; i < L - 1; i++) {
for (int j = 0; j + (2 << i) <= (int)a.size(); j++) {
dp[i + 1][j] = min(dp[i][j], dp[i][j + (1 << i)]);
}
}
}
int query(int l, int r) {
int t = __lg(r - l);
return min(dp[t][l], dp[t][r - (1 << t)]);
}
};
struct RUPQ {
int size;
vector<int64_t> fenw;
RUPQ(int n) : size(n), fenw(n + 1) {}
void add(int l, int r, int v) {
auto Add = [&](int i, int x) {
for (i++; i <= size; i += i & -i) {
fenw[i] += x;
}
};
Add(l, v);
Add(r, -v);
}
int64_t get(int i) {
int64_t ans = 0;
for (i++; i > 0; i -= i & -i) {
ans += fenw[i];
}
return ans;
}
};
struct query {
int i, S, T, X;
long long Y;
};
struct checkpoint {
int P, C;
bool operator<(const checkpoint& other) const {
return C < other.C;
}
};
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, m, q;
cin >> n >> m >> q;
vector<vector<pair<int, int>>> g(n);
for (int i = 0; i < n - 1; i++) {
int x, y;
cin >> x >> y;
x--, y--;
g[x].push_back({y, i});
g[y].push_back({x, i});
}
vector<int> tin(n), tout(n), depth(n), edge(n - 1), val(2 * n), tour(2 * n), first(n);
int timer = 0, pos = 0;
auto DFS = [&](auto&& self, int u, int p) -> void {
tin[u] = timer++;
val[pos] = depth[u];
first[u] = pos;
tour[pos++] = u;
for (auto [v, i] : g[u]) {
if (v != p) {
edge[i] = v;
depth[v] = depth[u] + 1;
self(self, v, u);
val[pos] = depth[u];
tour[pos++] = u;
}
}
tout[u] = timer;
};
DFS(DFS, 0, -1);
RMQ rmq(val);
auto LCA = [&](int u, int v) {
if (first[u] > first[v]) {
swap(u, v);
}
int p = rmq.query(first[u], first[v] + 1);
return tour[p];
};
vector<checkpoint> points(m);
for (auto &[P, C] : points) {
cin >> P >> C;
P--;
P = edge[P];
}
vector<query> Queries(q);
vector<int> ans(q);
for (auto &[i, S, T, X, Y] : Queries) {
cin >> S >> T >> X >> Y;
S--, T--;
}
for (int i = 0; i < q; i++) {
Queries[i].i = i;
}
sort(points.begin(), points.end());
RUPQ in(n), out(n);
for (auto [P, C] : points) {
out.add(tin[P], tout[P], +1);
}
auto Solve = [&](auto&& self, int l, int r, vector<query>& queries) -> void {
if (r - l == 1) {
for (auto [i, S, T, X, Y] : queries) {
ans[i] = X - (out.get(tin[S]) + out.get(tin[T]) - 2 * out.get(tin[LCA(S, T)]));
}
} else {
int mid = (l + r) / 2;
for (int i = l; i < mid; i++) {
in.add(tin[points[i].P], tout[points[i].P], points[i].C);
out.add(tin[points[i].P], tout[points[i].P], -1);
}
vector<query> lqueries, rqueries;
for (auto [i, S, T, X, Y] : queries) {
auto value = in.get(tin[S]) + in.get(tin[T]) - 2 * in.get(tin[LCA(S, T)]);
if (value > Y) {
lqueries.push_back({i, S, T, X, Y});
} else {
rqueries.push_back({i, S, T, X, Y});
}
}
vector<query>().swap(queries);
self(self, mid, r, rqueries);
vector<query>().swap(rqueries);
for (int i = l; i < mid; i++) {
in.add(tin[points[i].P], tout[points[i].P], -points[i].C);
out.add(tin[points[i].P], tout[points[i].P], +1);
}
self(self, l, mid, lqueries);
vector<query>().swap(lqueries);
}
};
Solve(Solve, 0, m + 1, Queries);
for (int i = 0; i < q; i++) {
cout << max(-1, ans[i]) << "\n";
}
}
