#include <iostream>
#include <vector>
#include <map>
using namespace std;
const int N = (1<<17) + 1;
vector<pair<int, int>> nei[N];
vector<int> vec[N];
int Par[N][20], hei[N], inv[N], cur;
map<int, int> mp, mp2;
struct node{
node *lc, *rc;
int cnt = 0, sum = 0;
} *seg[N<<1];
node* insert(node* cur, int t, int i, int v, int st = 1, int en = N){
if (i >= en or i < st)
return cur;
node* nw = new node();
if (en - st == 1){
nw->cnt = cur->cnt + t;
nw->sum = cur->sum + t * v;
return nw;
}
int mid = (st + en) / 2;
nw->lc = insert(cur->lc, t, i, v, st, mid);
nw->rc = insert(cur->rc, t, i, v, mid, en);
nw->sum = nw->lc->sum + nw->rc->sum;
nw->cnt = nw->lc->cnt + nw->rc->cnt;
return nw;
}
int get(node *cur, int k, int st = 1, int en = N){
if (k == 0)
return 0;
if (en - st == 1)
return cur->sum;
int mid = (st + en) / 2;
if (k < mid)
return get(cur->lc, k, st, mid);
return get(cur->rc, k, mid, en) + cur->lc->sum;
}
int getCnt(node *cur, int k, int st = 1, int en = N){
if (k == 0)
return 0;
if (en - st == 1)
return cur->cnt;
int mid = (st + en) / 2;
if (k < mid)
return getCnt(cur->lc, k, st, mid);
return getCnt(cur->rc, k, mid, en) + cur->lc->cnt;
}
node* build(int n){
// cout<<n<<endl;
node *nw = new node();
if (n == 1)
return nw;
nw->lc = build(n / 2);
nw->rc = build(n / 2);
return nw;
}
void dfs(int u, int p){
Par[u][0] = p;
hei[u] = hei[p] + 1;
for (int i=0;i<17;i++)
Par[u][i+1] = Par[Par[u][i]][i];
for (auto [i, id] : nei[u]){
if (i == p)
continue;
seg[i] = insert(seg[u], 1, 0, 0);
for (int j : vec[id])
seg[i] = insert(seg[i], 1, mp2[j], j);
dfs(i, u);
}
}
int LCA(int u, int v){
if (hei[u] > hei[v])
swap(u, v);
for (int i=17; i+1; i--){
if ((1<<i) + hei[u] <= hei[v])
v = Par[v][i];
}
for (int i=17; i+1; i--){
if (Par[u][i] != Par[v][i])
u = Par[u][i], v = Par[v][i];
}
return (u == v ? u : Par[v][0]);
}
int 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);
mp[c];
}
for (auto [i, j] : mp)
mp2[i] = ++cur, inv[cur] = i;
// cout<<"done"<<endl;
seg[1] = build(N);
dfs(1, 0);
// return 0;
inv[cur + 1] = 1e9;
for (int i=1;i<=q;i++){
int s, t, x, y;
cin>>s>>t>>x>>y;
int lca = LCA(s, t);
int l = 0, r = cur + 1;
while (l + 1 < r){
int mid = (l + r) / 2, k = get(seg[s], mid) + get(seg[t], mid) - 2 * get(seg[lca], mid);
// cout<<mid<<" "<<get(seg[s], mid)<<" "<<get(seg[t], mid)<<" "<<get(seg[lca], mid)<<endl;
if (k <= y)
l = mid;
else
r = mid;
}
// cout<<s<<" "<<t<<" "<<lca<<endl;
int c1 = seg[s]->cnt + seg[t]->cnt - 2 * seg[lca]->cnt;
int c2 = getCnt(seg[s], r) + getCnt(seg[t], r) - 2 * getCnt(seg[lca], r);
int c3 = getCnt(seg[s], r-1) + getCnt(seg[t], r-1) - 2 * getCnt(seg[lca], r-1);
// cout<<"done"<<endl;
c1 -= c2;
c2 -= c3;
y -= get(seg[s], l) + get(seg[t], l) - 2 * get(seg[lca], l);
// cout<<"done"<<endl;
// cout<<l<<" "<<r<<" "<<inv[r]<<" "<<y<<endl;
c2 -= min(c2, y / inv[r]);
// cout<<"done"<<endl;
if (x < c1 + c2)
cout<<-1<<'\n';
else
cout<<x - c1 - c2<<'\n';
}
}
/*
10 7 9
1 8
6 3
5 9
7 9
3 1
3 4
10 1
2 6
5 6
9 4
7 4
7 4
2 4
7 4
7 4
1 4
8 6 5 3
3 9 8 0
4 7 6 15
7 4 9 3
6 4 8 0
9 10 5 16
5 3 2 4
2 8 4 3
6 1 3 3
*/
