/*
Author: Nguyen Chi Thanh - High School for the Gifted - VNU.HCM (i2528)
*/
#include <bits/stdc++.h>
using namespace std;
/* START OF TEMPALTE */
#define int long long
#define ll long long
#define ull unsigned long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define popcount __builtin_popcountll
#define all(x) (x).begin(), (x).end()
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(x) (1ll << (x))
#define SZ(a) ((int32_t)a.size())
#define debug(a, l, r) {for (int _i = (l); _i <= (r); ++_i) cout << (a)[_i] << ' '; cout << '\n';}
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y) {
x = y;
return true;
} else return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y) {
x = y;
return true;
} else return false;
}
/* END OF TEMPALTE */
const int MAXN = 1e5 + 5;
const int LG = 17;
struct Checkpoint {
int u, v, cost;
bool operator < (const Checkpoint &other) const {
return cost < other.cost;
}
};
struct Query {
int s, t, numGold, numSilver, id;
};
struct FenwickTree {
int n;
vector<int> fen;
FenwickTree(int _n) : n(_n), fen(n + 5, 0) {}
void reset() {fill(all(fen), 0);}
void update(int idx, int v) {
for (int i = idx; i <= n; i += i & -i)
fen[i] += v;
}
int get(int idx) {
int sum = 0;
for (int i = idx; i; i -= i & -i)
sum += fen[i];
return sum;
}
void updateRange(int l, int r, int v) {
update(l, v);
update(r + 1, -v);
}
};
int n, m, q;
int st[MAXN], en[MAXN], depth[MAXN], up[LG + 1][MAXN];
vector<int> adj[MAXN];
pii edges[MAXN];
Checkpoint checkpoints[MAXN];
Query queries[MAXN];
int passCheckpoints[MAXN];
void init() {
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);
edges[i] = {u, v};
}
int timer = 0;
function<void(int, int)> preDfs = [&] (int u, int par) {
st[u] = ++timer;
up[0][u] = par;
for (int j = 1; j <= LG; ++j)
up[j][u] = up[j - 1][up[j - 1][u]];
for (int v : adj[u]) {
if (v == par) continue;
depth[v] = depth[u] + 1;
preDfs(v, u);
}
en[u] = timer;
};
preDfs(1, 0);
for (int i = 1; i <= m; ++i) {
int eid, cost; cin >> eid >> cost;
int u = edges[eid].fi, v = edges[eid].se;
if (depth[u] > depth[v]) swap(u, v);
checkpoints[i] = {u, v, cost};
}
sort(checkpoints + 1, checkpoints + m + 1);
for (int i = 1; i <= q; ++i) {
int s, t, g, c; cin >> s >> t >> g >> c;
queries[i] = {s, t, g, c, i};
}
}
int lift(int u, int k) {
for (int j = 0; j <= LG; ++j)
if (BIT(k, j)) u = up[j][u];
return u;
}
int lca(int u, int v) {
if (depth[u] > depth[v]) swap(u, v);
int diff = depth[v] - depth[u];
v = lift(v, diff);
if (u == v) return u;
for (int j = LG; j >= 0; --j) {
if (up[j][u] != up[j][v]) {
u = up[j][u];
v = up[j][v];
}
}
return up[0][u];
}
void parallelBinSearch() {
vector<int> left(q + 5, 0), right(q + 5, m);
vector<vector<Query>> cand(m + 5, vector<Query>());
FenwickTree fen(n), fenCnt(n);
// int iter = 1;
while (1) {
bool any = 0;
for (int i = 1; i <= q; ++i) {
if (left[i] <= right[i]) {
int mid = (left[i] + right[i]) >> 1;
cand[mid].push_back(queries[i]);
any = 1;
}
}
if (!any) break;
fen.reset(); fenCnt.reset();
for (int mid = 0; mid <= m; ++mid) {
// cout << mid << ":\n";
if (mid >= 1) {
Checkpoint curcheck = checkpoints[mid];
// cout << "UPDATE ";
// cout << curcheck.u << ' ' << curcheck.v << ' ' << curcheck.cost << '\n';
int target = curcheck.v, cost = curcheck.cost;
fen.updateRange(st[target], en[target], cost);
fenCnt.updateRange(st[target], en[target], 1);
}
for (auto &qry : cand[mid]) {
// cout << qry.s << ' ' << qry.t << ' ' << qry.numGold << ' ' << qry.numSilver << ' ' << qry.id << '\n';
int s = qry.s, t = qry.t, x = lca(s, t), id = qry.id;
int pathCost = fen.get(st[s]) + fen.get(st[t]) - 2 * fen.get(st[x]);
if (pathCost <= qry.numSilver) {
int cntCheckpoints = fenCnt.get(st[s]) + fenCnt.get(st[t]) - 2 * fenCnt.get(st[x]);
passCheckpoints[id] = cntCheckpoints;
left[id] = mid + 1;
} else right[id] = mid - 1;
}
}
for (int mid = 0; mid <= m; ++mid) cand[mid].clear();
}
}
void answerQueries() {
FenwickTree fen(n);
for (int i = 1; i <= m; ++i) {
int target = checkpoints[i].v;
fen.updateRange(st[target], en[target], 1);
}
for (int i = 1; i <= q; ++i) {
Query qry = queries[i];
int s = qry.s, t = qry.t, numGold = qry.numGold, x = lca(s, t);
int numCheck = fen.get(st[s]) + fen.get(st[t]) - 2 * fen.get(st[x]);
int needGold = numCheck - passCheckpoints[i];
cout << (needGold <= numGold ? numGold - needGold : -1) << '\n';
}
}
void solve() {
parallelBinSearch();
answerQueries();
}
signed main() {
#ifdef NCTHANH
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
init();
solve();
return 0;
}
