#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, minC = INF, maxC, zeroes[2 * maxn], a[2 * maxn], L[maxn], R[maxn], curChain, curPos, pos[maxn], chainID[maxn], chainHead[maxn], sz[maxn], h[maxn], par[maxn];
vector<int> adj[maxn], weightAtPos[maxn];
pair<int, int> E[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;
}
pair<int, ll> add(pair<int, ll> A, pair<int, ll> B) {
return make_pair(A.F + B.F, A.S + B.S);
}
class wavelet_tree {
public:
int low, high;
wavelet_tree *l, *r;
vector<int> freq;
vector<ll> pref;
wavelet_tree() : low(0), high(0), l(nullptr), r(nullptr) {}
wavelet_tree(int *from, int *to, int x, int y) {
low = x; high = y;
if (from >= to) return;
if (high == low) {
pref.reserve(to - from + 1);
freq.reserve(to - from + 1);
freq.pb(0); pref.pb(0);
for (auto it = from; it != to; it++)
freq.pb(freq.back() + 1), pref.pb(pref.back() + *it);
return;
}
int mid = (low + high) >> 1;
auto lessThanMid
= [mid](int x) { return x <= mid; };
freq.reserve(to - from + 1); freq.pb(0);
pref.reserve(to - from + 1); pref.pb(0);
for (auto it = from; it != to; it++) {
freq.pb(freq.back() + lessThanMid(*it));
pref.pb(pref.back() + *it);
}
auto pivot = stable_partition(from, to, lessThanMid);
l = new wavelet_tree(from, pivot, low, mid);
r = new wavelet_tree(pivot, to, mid + 1, high);
}
pair<int, ll> kOrLess(int l, int r, int k) {
if (l > r || k < low) return make_pair(0, 0);
if (high <= k) return make_pair(r - l + 1, pref[r] - pref[l - 1]);
int LtCount = freq[l - 1], RtCount = freq[r];
return add(this -> l -> kOrLess(LtCount + 1, RtCount, k), this -> r -> kOrLess(l - LtCount, r - RtCount, k));
}
} wt;
struct BIT {
int bit[maxn];
void update(int id, int v) {
for (; id <= n; id += id & -id)
bit[id] += v;
}
int get(int id) {
int res = 0;
for (; id > 0; id -= id & -id)
res += bit[id];
return res;
}
int getRange(int l, int r) {
if (l > r) return 0;
return get(r) - get(l - 1);
}
} BIT;
int getGold(int u, int v) {
int lca = LCA(u, v), res = 0;
while (chainID[u] != chainID[lca]) {
res += BIT.getRange(pos[chainHead[chainID[u]]], pos[u]);
u = par[chainHead[chainID[u]]];
}
while (chainID[v] != chainID[lca]) {
res += BIT.getRange(pos[chainHead[chainID[v]]], pos[v]);
v = par[chainHead[chainID[v]]];
}
if (pos[u] > pos[v]) swap(u, v);
res += BIT.getRange(pos[u] + 1, pos[v]);
return res;
}
int getZeroes(int l, int r) {
return zeroes[r] - zeroes[l - 1];
}
pair<int, ll> getPath(int u, int v, int x) {
int lca = LCA(u, v);
pair<int, ll> res = make_pair(0, 0);
while (chainID[u] != chainID[lca]) {
res = add(res, wt.kOrLess(L[pos[chainHead[chainID[u]]]], R[pos[u]], x));
res.F -= getZeroes(L[pos[chainHead[chainID[u]]]], R[pos[u]]);
u = par[chainHead[chainID[u]]];
}
while (chainID[v] != chainID[lca]) {
res = add(res, wt.kOrLess(L[pos[chainHead[chainID[v]]]], R[pos[v]], x));
res.F -= getZeroes(L[pos[chainHead[chainID[v]]]], R[pos[v]]);
v = par[chainHead[chainID[v]]];
}
if (pos[u] > pos[v]) swap(u, v);
res = add(res, wt.kOrLess(L[pos[u] + 1], R[pos[v]], x));
res.F -= getZeroes(L[pos[u] + 1], R[pos[v]]);
return res;
}
int query(int u, int v, int x, ll y) {
int l = minC - 1, r = maxC, lim = -1;
int gold = getGold(u, v), recGold = 0;
ll sil = 0;
while (l <= r) {
int mid = (l + r) >> 1;
auto get = getPath(u, v, mid);
if (get.S <= y) {
sil = get.S;
recGold = get.F;
lim = mid;
l = mid + 1;
} else r = mid - 1;
}
if (lim == -1) return (x >= gold ? x - gold : -1);
if (lim < maxC) recGold += (y - sil) / (lim + 1);
int fin = x - gold + recGold;
return fin < 0 ? -1 : fin;
}
void solve() {
cin >> n >> m >> q;
for (int i = 1, u, v; i < n; ++i) {
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
E[i] = make_pair(u, v);
}
curChain = curPos = 1;
dfs(1); hld(1);
for (int i = 1, p, c; i <= m; ++i) {
cin >> p >> c;
int u = E[p].F, v = E[p].S;
if (pos[u] < pos[v]) swap(u, v);
weightAtPos[pos[u]].push_back(c);
BIT.update(pos[u], 1);
maximize(maxC, c);
minimize(minC, c);
}
int cur = 0;
for (int i = 1; i <= n; ++i) {
if (weightAtPos[i].empty()) {
L[i] = R[i] = cur + 1;
a[cur++] = 0;
continue;
}
L[i] = cur + 1; R[i] = cur + (int) weightAtPos[i].size();
for (int x: weightAtPos[i])
a[cur++] = x;
}
for (int i = 1; i <= cur; ++i)
zeroes[i] = zeroes[i - 1] + (a[i - 1] == 0);
wt = wavelet_tree(a, a + cur, 0, maxC);
while (q--) {
int s, t, x;
ll y;
cin >> s >> t >> x >> y;
cout << query(s, t, x, y) << 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;
}
