#include <bits/stdc++.h>
#define int long long
using namespace std;
string to_string(string s) { return s; }
template <typename T> string to_string(T v) {
bool first = true;
string res = "[";
for (const auto &x : v) {
if (!first)
res += ", ";
first = false;
res += to_string(x);
}
res += "]";
return res;
}
void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
cout << ' ' << to_string(H);
dbg_out(T...);
}
#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif
template <class T> class Fenwick {
public:
int lim;
vector<T> bit;
Fenwick(int n) : lim(n + 1), bit(lim) {}
void upd(int pos, T val) {
for (pos++; pos < lim; pos += pos & -pos)
bit[pos] += val;
}
T sum(int r) { // < r
T ret = 0;
for (; r; r -= r & -r)
ret += bit[r];
return ret;
}
T sum(int l, int r) { // [l, r)
return sum(r) - sum(l);
}
};
const int MAXN = 1e5;
const int MAXP = 17;
int par[MAXP][MAXN];
vector<int> adj[MAXN];
int depth[MAXN], tin[MAXN], tout[MAXN];
int T;
void dfs(int u, int p) {
tin[u] = T++;
par[0][u] = p;
for (int i = 0; i < MAXP - 1; ++i)
par[i + 1][u] = par[i][par[i][u]];
for (int v : adj[u])
if (v != p) {
depth[v] = depth[u] + 1;
dfs(v, u);
}
tout[u] = T++;
}
int getLca(int u, int v) {
if (depth[u] < depth[v])
swap(u, v);
int diff = depth[u] - depth[v];
for (int p = 0; p < MAXP; ++p)
if ((1 << p) & diff)
u = par[p][u];
if (u == v)
return u;
for (int p = MAXP - 1; p >= 0; --p)
if (par[p][u] != par[p][v])
u = par[p][u], v = par[p][v];
return par[0][u];
}
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(0);
int nbSommets, nbPoids, nbRequetes;
cin >> nbSommets >> nbPoids >> nbRequetes;
vector<pair<int, int>> edges(nbSommets - 1);
for (auto &[u, v] : edges) {
cin >> u >> v;
--u, --v;
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(0, 0);
vector<pair<int, int>> weights(nbPoids);
for (int i = 0; i < nbPoids; ++i) {
int p, c;
cin >> p >> c;
--p;
auto [u, v] = edges[p];
if (depth[u] > depth[v])
swap(u, v);
weights[i] = pair(c, v);
}
sort(weights.begin(), weights.end());
vector<tuple<int, int, int, int>> queries(nbRequetes);
for (auto &[s, t, gold, silver] : queries) {
cin >> s >> t >> gold >> silver;
--s, --t;
if (tin[s] > tin[t])
swap(s, t);
}
dbg(nbSommets, nbPoids, nbRequetes);
vector<int> lca(nbRequetes);
for (int i = 0; i < nbRequetes; ++i) {
auto [s, t, gold, silver] = queries[i];
lca[i] = getLca(s, t);
dbg(s, t, lca[i]);
}
vector<int> lo(nbRequetes), up(nbRequetes, nbPoids);
vector<int> cntFinal(nbRequetes, 1e18);
vector<int> cntTotal(nbRequetes);
while (true) {
bool change = false;
vector<vector<int>> needCheck(nbPoids + 1);
for (int i = 0; i < nbRequetes; ++i) {
if (lo[i] < up[i]) {
int mid = (lo[i] + up[i] + 1) / 2;
change = true;
needCheck[mid].push_back(i);
} else
needCheck[lo[i]].push_back(i);
}
Fenwick<int> fenCnt(T), fenSum(T);
for (int iPoids = 0; iPoids <= nbPoids; ++iPoids) {
for (int iRequete : needCheck[iPoids]) {
int l = lca[iRequete];
auto [u, v, gold, silver] = queries[iRequete];
int cnt = fenCnt.sum(tin[u] + 1) + fenCnt.sum(tin[v] + 1) -
2 * fenCnt.sum(tin[l] + 1);
int sum = fenSum.sum(tin[u] + 1) + fenSum.sum(tin[v] + 1) -
2 * fenSum.sum(tin[l] + 1);
cntFinal[iRequete] = cnt;
if (sum <= silver)
lo[iRequete] = iPoids;
else
up[iRequete] = iPoids - 1;
}
if (iPoids < nbPoids) {
auto [c, u] = weights[iPoids];
fenCnt.upd(tin[u], 1);
fenCnt.upd(tout[u], -1);
fenSum.upd(tin[u], c);
fenSum.upd(tout[u], -c);
}
}
for (int iRequete = 0; iRequete < nbRequetes; ++iRequete) {
int l = lca[iRequete];
auto [u, v, gold, silver] = queries[iRequete];
int cnt = fenCnt.sum(tin[u] + 1) + fenCnt.sum(tin[v] + 1) -
2 * fenCnt.sum(tin[l] + 1);
cntTotal[iRequete] = cnt;
}
if (!change)
break;
}
for (int i = 0; i < nbRequetes; ++i) {
auto [u, v, gold, silver] = queries[i];
dbg(cntFinal[i], cntTotal[i]);
cout << max(-1LL, gold - (cntTotal[i] - cntFinal[i])) << endl;
}
}
