// Author: caption_mingle
#include "bits/stdc++.h"
using namespace std;
#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
#define int long long
const int mod = 1e9 + 7;
const int inf = 2e9;
const int N = 1e5 + 7;
int n, up[N][20], m, h[N], q, L[N], R[N];
int cnt[N], in[N], out[N], ans[N], st[N];
pair<int, int> edge[N], que[N];
int timer;
vector<int> g[N];
struct citizen {
int u, v, p, gc, sc;
} a[N];
vector<int> ev[N];
void dfs(int u, int p) {
in[u] = ++timer;
st[timer] = u;
for(int i = 1; i < 20; i++) up[u][i] = up[up[u][i - 1]][i - 1];
for(int v : g[u]) {
if(v == p) continue;
up[v][0] = u;
h[v] = h[u] + 1;
dfs(v, u);
}
out[u] = timer;
}
int lca(int u, int v) {
if(h[u] < h[v]) swap(u, v);
int k = h[u] - h[v];
for(int i = 0; (1 << i) <= k; i++) {
if(k >> i & 1) u = up[u][i];
}
if(u == v) return u;
for(int i = 19; i >= 0; i--) {
if(up[u][i] != up[v][i]) {
u = up[u][i];
v = up[v][i];
}
}
return up[u][0];
}
struct BIT {
vector<ll> bit;
int n;
BIT() {}
BIT(int n) : n(n) {
bit.resize(n + 1, 0);
}
void update(int u, int x) {
for(; u <= n; u += (u & -u)) bit[u] += x;
}
ll get(int u) {
ll ans = 0;
for(; u > 0; u -= (u & -u)) ans += bit[u];
return ans;
}
void update(int l, int r, int x) {
update(l, x);
update(r + 1, -x);
}
};
signed main() {
cin.tie(0) -> sync_with_stdio(0);
#define task ""
if(fopen(task ".INP", "r")) {
freopen(task ".INP", "r", stdin);
freopen(task ".OUT", "w", stdout);
}
cin >> n >> m >> q;
for(int i = 1; i < n; i++) {
int u, v; cin >> u >> v;
g[u].pb(v);
g[v].pb(u);
edge[i] = {u, v};
}
dfs(1, 0);
for(int i = 1; i <= m; i++) {
int id, p; cin >> id >> p;
auto& [u, v] = edge[id];
if(u == up[v][0]) swap(u, v);
cnt[u]++;
que[i] = {p, id};
}
sort(que + 1, que + m + 1);
for(int i = 1; i <= q; i++) {
int u, v, gc, sc; cin >> u >> v >> gc >> sc;
int p = lca(u, v);
a[i] = {u, v, p, gc, sc};
L[i] = 1, R[i] = m;
}
for(int i = 1; i <= n; i++) {
int u = st[i];
cnt[u] += cnt[up[u][0]];
}
while(1) {
bool ok = 0;
for(int i = 1; i <= q; i++) {
if(L[i] <= R[i]) {
int m = (L[i] + R[i]) >> 1;
ev[m].pb(i);
ok = 1;
}
}
if(!ok) break;
BIT bit1(n), bit2(n);
for(int i = 1; i <= m; i++) {
auto [p, eid] = que[i];
auto [u, v] = edge[eid];
bit1.update(in[u], out[u], 1);
bit2.update(in[u], out[u], p);
for(int id : ev[i]) {
auto [u, v, p, gc, sc] = a[id];
ll req = bit2.get(in[u]) + bit2.get(in[v]) - 2 * bit2.get(in[p]);
if(req <= sc) {
L[id] = i + 1;
ans[id] = bit1.get(in[u]) + bit1.get(in[v]) - 2 * bit1.get(in[p]);
} else R[id] = i - 1;
}
ev[i].clear();
}
}
for(int i = 1; i <= q; i++) {
auto [u, v, p, gc, sc] = a[i];
int tot = cnt[u] + cnt[v] - 2 * cnt[p];
// cerr << tot << ' ' << ans[i] << ln;
if(tot - ans[i] <= gc) {
cout << gc - tot + ans[i] << ln;
} else {
cout << -1 << ln;
}
}
cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}
