#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define sz(x) (int) x.size()
#define all(x) x.begin(), x.end()
typedef long long ll;
typedef pair <int, int> ii;
const int N = 3e5 + 5;
const int mod = 998244353;
struct Bit {
int n; vector <ll> bit;
Bit (int _n): n(_n), bit(_n + 2, 0) {};
void up(int x, int val) {
for(; x <= n; x += (x & -x)) bit[x] += val;
}
ll get(int x) {
ll ans = 0;
for(; x; x -= (x & -x)) ans += bit[x];
return ans;
}
void up_range(int l, int r, int val) {
up(l, val), up(r + 1, -val);
}
} B1(N), B2(N);
int n, m, q, timer = 0, p[20][N], in[N], ou[N], id[N], ans[N];
vector <ii> ed[N], save;
void dfs(int u, int par) {
p[0][u] = par;
for(int i = 1; i < 20; i++)
p[i][u] = p[i - 1][p[i - 1][u]];
in[u] = ++timer;
for(auto v: ed[u]) {
if (v.f == par) continue;
id[v.s] = v.f;
dfs(v.f, u);
}
ou[u] = timer;
}
bool is(int a, int b) {
return in[a] <= in[b] && ou[b] <= ou[a];
}
int lca(int a, int b) {
if (is(a, b)) return a;
if (is(b, a)) return b;
for(int i = 19; i >= 0; i--) {
if (!is(p[i][a], b))
a = p[i][a];
}
return p[0][a];
}
ll sum(int a, int b, Bit& B) {
int c = lca(a, b);
return B.get(in[a]) + B.get(in[b]) - 2 * B.get(in[c]);
}
void para(int l, int r, vector <vector <ll>>& queries) {
if (l > r || !sz(queries)) return;
int m = (l + r) / 2;
for(int i = l; i <= m; i++) {
int c = save[i].f, p = save[i].s;
B1.up_range(in[p], ou[p], c);
B2.up_range(in[p], ou[p], 1);
}
vector <vector <ll>> win, lose;
for(auto x: queries) {
if (sum(x[0], x[1], B1) <= x[3]) {
ans[x[4]] -= sum(x[0], x[1], B2);
win.push_back(x);
win.back()[3] -= sum(x[0], x[1], B1);
} else {
lose.push_back(x);
}
}
for(int i = l; i <= m; i++) {
int c = save[i].f, p = save[i].s;
B1.up_range(in[p], ou[p], -c);
B2.up_range(in[p], ou[p], -1);
}
if (l != r)
para(l, m, lose); vector <vector <ll>> ().swap(lose);
para(m + 1, r, win); vector <vector <ll>> ().swap(win);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
for(int i = 1; i < n; i++) {
int u, v; cin >> u >> v;
ed[u].push_back({v, i});
ed[v].push_back({u, i});
}
dfs(1, 1);
for(int i = 1; i <= m; i++) {
int p, c; cin >> p >> c;
p = id[p]; B2.up_range(in[p], ou[p], 1);
save.push_back({c, p});
}
sort(all(save));
vector <vector <ll>> queries;
for(int i = 0; i < q; i++) {
int s, t, x, y; cin >> s >> t >> x >> y;
ans[i] += sum(s, t, B2);
queries.push_back({s, t, x, y, i});
}
for(auto x: save)
B2.up_range(in[x.s], ou[x.s], -1);
para(0, sz(save) - 1, queries);
for(int i = 0; i < q; i++)
cout << max(-1ll, queries[i][2] - ans[i]) << "\n";
return 0;
}
