/*ㅤ∧＿∧
( ･∀･)
( つ┳⊃
ε (_)へ⌒ヽﾌ
( ( ･ω･)
◎―◎ ⊃ ⊃
BePhuongSuperSuwi
From TK4 - CHT
ㅤㅤ／ ⌒＼____
/・ ） \
/ノへ ノ /|
ノ ＼\ |/_/_/*/
#include<bits/stdc++.h>
#define task "main"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define int long long
#define pb push_back
#define fi first
#define se second
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii, ii>
#define base 341
#define MASK(i) (1ll << i)
#define oo 1e18
#define isOn(x,i) ((x) & MASK(i))
#define bitOn(x,i) ((x) | MASK(i))
#define bitOff(x,i) ((x) & ~MASK(i))
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define __lcm(a,b) (1ll * ((a) / __gcd((a), (b))) * (b))
using namespace std;
//using namespace __gnu_pbds;
const int maxn = 1e5 + 5;
int n, m, test, l[maxn], r[maxn];
vector <int> query[maxn];
struct pt{
int pos, val;
} q[maxn];
bool ss(pt a, pt b) {
return a.val < b.val;
}
vector<ii> v[maxn];
int sz[maxn], Head[maxn], h[maxn], par[maxn], Pos[maxn], Id[maxn], chain, timer, tin[maxn], tout[maxn], ed[maxn];
void dfs(int u, int p) {
sz[u] = 1;
for (auto e : v[u]) {
int x = e.fi, y = e.se;
if (x == p) continue;
h[x] = h[u] + 1;
par[x] = u;
ed[y] = x;
dfs(x, u);
sz[u] += sz[x];
}
}
void hld(int u, int p) {
if (!Head[chain]) {
Head[chain] = u;
}
Id[u] = chain;
Pos[u] = tin[u] = ++timer;
int nxt = 0;
for (auto e: v[u]) {
int x = e.fi;
if (x == p) continue;
if (nxt == 0 || sz[nxt] < sz[x]) nxt = x;
}
if (nxt) hld(nxt, u);
for (auto e : v[u]) {
int x = e.fi;
if (x == p || x == nxt) continue;
chain++;
hld(x, u);
}
tout[u] = timer;
}
struct HLD{
int st[4 * maxn];
void update(int id, int l, int r, int pos, int val) {
if (l == r) {
st[id] += val;
return;
}
int m = (l + r) / 2;
if (pos <= m) update(id * 2, l, m, pos, val);
else update(id * 2 + 1, m + 1, r, pos, val);
st[id] = st[id * 2] + st[id * 2 + 1];
}
int get(int id, int l, int r, int u, int v) {
if (u > r || v < l) return 0;
if (l >= u && r <= v) return st[id];
int m = (l + r)/2;
return get(id * 2, l, m, u, v) + get(id * 2 + 1, m + 1, r, u, v);
}
void init() {
for (int i = 0; i <= 4 * n; i++) st[i] = 0;
}
int Query(int u, int v) {
int ans = 0;
while (Id[u] != Id[v]) {
if (h[Head[Id[u]]] > h[Head[Id[v]]]) swap(u,v);
ans += get(1,1,n,Pos[Head[Id[v]]], Pos[v]);
v = par[Head[Id[v]]];
}
if (h[u] > h[v]) swap(u,v);
ans += get(1,1,n,Pos[u] + 1, Pos[v]);
return ans;
}
} hld1, hld2;
int s[maxn], t[maxn], x[maxn], y[maxn], res[maxn];
main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
if(fopen(task".inp","r")) {
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
cin >> n >> m >> test;
for (int i = 1; i < n; i++) {
int l, r;
cin >> l >> r;
v[l].pb({r, i}); v[r].pb({l, i});
}
for (int i = 1; i <= m; i++) {
cin >> q[i].pos >> q[i].val;
}
sort(q + 1, q + m + 1, ss);
for (int i = 1; i <= test; i++) {
cin >> s[i] >> t[i] >> x[i] >> y[i];
l[i] = 0, r[i] = m, res[i] = -1;
}
dfs(1, -1);
chain = 1;
hld(1, -1);
while(true) {
bool ok = false;
for (int i = 1; i <= test; i++) {
if (l[i] > r[i]) continue;
ok = true;
int mid = (l[i] + r[i])/2;
query[mid].pb(i);
}
if (!ok) break;
//reset_ctdl;
hld1.init();
hld2.init();
for (int mid = 0; mid <= m; mid++) {
if (mid > 0) {
int id = q[mid].pos, val = q[mid].val;
hld2.update(1, 1, n, tin[ed[id]], 1);
hld1.update(1, 1, n, tin[ed[id]], val);
}
for (auto id : query[mid]) {
if (hld1.Query(s[id], t[id]) <= y[id]) {
res[id] = hld2.Query(s[id], t[id]);
l[id] = mid + 1;
}
else r[id] = mid - 1;
}
query[mid].clear();
}
}
hld2.init();
for (int i = 1; i <= m; i++) {
int id = q[i].pos;
hld2.update(1, 1, n, tin[ed[id]], 1);
}
for (int i = 1; i <= test; i++) {
// cout << res[i] << " ";
int val = x[i] - (hld2.Query(s[i], t[i]) - res[i]);
// cout << x[i] << " " << hld2.Query(s[i], t[i]) << " ";
if (val < 0) cout << "-1" << endl;
else cout << val << endl;
}
}
