#include <bits/stdc++.h>
// #include <ext/rope>
// #include <ext/pb_ds/assoc_container.hpp>
// using namespace __gnu_pbds;
// using namespace __gnu_cxx;
using namespace std;
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
// #define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define bit(mask, i) ((mask >> i) & 1)
#define el '\n'
#define F first
#define S second
template <class X, class Y> bool maximize(X &x, const Y &y) { return (x < y ? x = y, 1 : 0); }
template <class X, class Y> bool minimize(X &x, const Y &y) { return (x > y ? x = y, 1 : 0); }
const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7;
const int MULTI = 0;
const ld eps = 1e-9;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0}; // R D L U
const int ddx[4] = {-1, 1, 1, -1}, ddy[4] = {1, 1, -1, -1}; // UR DR DL UL
const char cx[4] = {'R', 'D', 'L', 'U'};
const ll base = 31;
const int nMOD = 2;
const ll mods[] = {(ll)1e9 + 10777, (ll)1e9 + 19777, (ll)1e9 + 3, (ll)1e9 + 3777};
const int maxn = 1e5 + 5;
int n, m, q, cnt[maxn], l[maxn], r[maxn], A[maxn], B[maxn], L[maxn], S[maxn], T[maxn], X[maxn], curChain, curPos, sz[maxn], chainID[maxn], pos[maxn], chainHead[maxn], h[maxn], par[maxn];
vector<int> adj[maxn], queries[maxn];
ll Y[maxn];
pair<int, int> P[maxn];
void dfs(int u) {
sz[u] = 1;
for (int v: adj[u])
if (v != par[u]) {
par[v] = u;
h[v] = h[u] + 1;
dfs(v);
sz[u] += sz[v];
}
}
void hld(int u) {
if (!chainHead[curChain]) chainHead[curChain] = u;
chainID[u] = curChain; pos[u] = curPos++;
int nxt = 0;
for (int v: adj[u])
if (v != par[u] && sz[v] > sz[nxt])
nxt = v;
if (nxt) hld(nxt);
for (int v: adj[u])
if (v != par[u] && v != nxt) {
curChain++;
hld(v);
}
}
int LCA(int u, int v) {
while (chainID[u] != chainID[v])
if (chainID[u] > chainID[v])
u = par[chainHead[chainID[u]]];
else
v = par[chainHead[chainID[v]]];
return h[u] < h[v] ? u : v;
}
struct BIT {
ll bit[maxn];
void init() {
fill(bit + 1, bit + 1 + n, 0);
}
void update(int id, int v) {
for (; id <= n; id += id & -id)
bit[id] += v;
}
ll get(int id) {
ll res = 0;
for (; id > 0; id -= id & -id)
res += bit[id];
return res;
}
ll getRange(int l, int r) {
return l > r ? 0 : get(r) - get(l - 1);
}
} BIT[2];
void update(int u, int v, int id, int val) {
if (pos[u] < pos[v]) swap(u, v);
BIT[id].update(pos[u], val);
}
ll get(int u, int v, int id) {
int lca = LCA(u, v);
ll res = 0;
while (chainID[u] != chainID[lca]) {
res += BIT[id].getRange(pos[chainHead[chainID[u]]], pos[u]);
u = par[chainHead[chainID[u]]];
}
while (chainID[v] != chainID[lca]) {
res += BIT[id].getRange(pos[chainHead[chainID[v]]], pos[v]);
v = par[chainHead[chainID[v]]];
}
if (pos[u] > pos[v]) swap(u, v);
res += BIT[id].getRange(pos[u] + 1, pos[v]);
return res;
}
void solve() {
cin >> n >> m >> q;
for (int i = 1; i < n; ++i) {
cin >> A[i] >> B[i];
adj[A[i]].push_back(B[i]);
adj[B[i]].push_back(A[i]);
}
curChain = curPos = 1;
dfs(1); hld(1);
for (int i = 1; i <= m; ++i)
cin >> P[i].S >> P[i].F;
for (int i = 1; i <= q; ++i) {
cin >> S[i] >> T[i] >> X[i] >> Y[i];
L[i] = LCA(S[i], T[i]);
l[i] = 0; r[i] = m;
}
sort(P + 1, P + 1 + m);
while (true) {
for (int i = 0; i <= m; ++i)
queries[i].clear();
bool all_answered = true;
for (int i = 1; i <= q; ++i) {
if (l[i] > r[i]) continue;
all_answered = false;
queries[(l[i] + r[i]) >> 1].push_back(i);
}
if (all_answered) break;
BIT[0].init(); BIT[1].init();
for (int i = 1; i <= m; ++i) {
int u = A[P[i].S], v = B[P[i].S];
update(u, v, 0, 1);
}
for (int i = 0; i <= m; ++i) {
for (int j: queries[i]) {
ll s = get(S[j], T[j], 1);
if (s <= Y[j]) {
cnt[j] = get(S[j], T[j], 0);
l[j] = i + 1;
} else
r[j] = i - 1;
}
if (i < m) {
int val = P[i + 1].F;
int u = A[P[i + 1].S], v = B[P[i + 1].S];
update(u, v, 0, -1);
update(u, v, 1, val);
}
}
}
for (int i = 1; i <= q; ++i)
cout << max(X[i] - cnt[i], -1) << el;
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (!MULTI) solve();
else {
int test; cin >> test;
while (test--) solve();
}
return 0;
}
