#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int N = 1<<17, K = 320, B = 320;
vector<pair<int,int>> nei[N];
vector<int> vec[N], adj[N];
vector<pair<int, pair<int, int>>> ord;
long long inf = 2e18, arr[N], Sum[N], y[N];
int blk[N], st[N], en[N], s[N], t[N], x[N], cr0, cr1, cr2 = 1, Cnt;
int cnt1[N], cnt2[N], num[N], seen[N], Ans[N], ind[N], dv[N], lv[N], Par[N];
void block(vector<int> me){
++cr1;
for (int j : me)
blk[j] = cr1;
}
void dfs0(int u, int p){
for (auto [i, id] : nei[u]){
if (i == p)
continue;
lv[i] = lv[u];
for (int j : vec[id]){
adj[lv[i]].push_back(++cr2);
num[cr2] = j;
lv[i] = cr2;
}
dfs0(i, u);
}
}
vector<int> dfs(int u, int p){
st[u] = ++cr0;
vector<int> me;
for (int i : adj[u]){
Par[i] = u;
vector<int> nw = dfs(i, u);
me.insert(me.end(), nw.begin(), nw.end());
if (me.size() >= K)
block(me), me = {};
}
en[u] = ++cr0;
me.push_back(u);
return me;
}
void toggle(int id){
if (num[id] == 0)
return;
int cur = ind[id], d = dv[cur];
if (seen[id]){
Cnt--;
cnt1[cur]--;
cnt2[d]--;
Sum[d] -= num[id];
}
else{
Cnt++;
cnt1[cur]++;
cnt2[d]++;
Sum[d] += num[id];
}
seen[id] ^= 1;
}
void moveLR(int u, int v){
while (st[u] > st[v] or en[u] < en[v]){
toggle(u);
u = Par[u];
}
while (v != u){
toggle(v);
v = Par[v];
}
}
signed main(){
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n, m, q;
cin>>n>>m>>q;
for (int i=1, a, b;i<n;i++){
cin>>a>>b;
nei[a].push_back({b, i});
nei[b].push_back({a, i});
}
for (int i=1, p, c;i<=m;i++){
cin>>p>>c;
vec[p].push_back(c);
arr[i-1] = c;
}
sort(arr, arr + m);
m = unique(arr, arr + m) - arr;
for (int i=m;i<N;i++)
arr[i] = inf;
lv[1] = 1;
dfs0(1, 0);
block(dfs(1, 0));
for (int i=1;i<N;i++)
ind[i] = upper_bound(arr, arr + N, num[i] - 1) - arr, dv[i] = i / B;
for (int i=1;i<=q;i++){
cin>>s[i]>>t[i]>>x[i]>>y[i];
s[i] = lv[s[i]], t[i] = lv[t[i]];
ord.push_back({blk[s[i]], {t[i], i}});
}
sort(ord.begin(), ord.end());
int L = 1, R = 1;
for (auto [vl, pr] : ord){
int id = pr.second, cur = -1, d = -1, gld;
moveLR(L, s[id]);
moveLR(R, t[id]);
L = s[id], R = t[id], gld = Cnt;
while (arr[cur + B] != inf and y[id] >= Sum[d + 1])
d++, cur += B, y[id] -= Sum[d], gld -= cnt2[d];
while (arr[cur+1] != inf and arr[cur + 1] * cnt1[cur + 1] <= y[id])
cur++, y[id] -= arr[cur] * cnt1[cur], gld -= cnt1[cur];
Ans[id] = max(-1LL, x[id] - gld + y[id] / arr[++cur]);
}
for (int i=1;i<=q;i++)
cout<<Ans[i]<<' ';
cout<<'\n';
}
