#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
const int mod = 998244353;
const int N = 1e5;
int n, m, q;
vector<int > g[N+10];
vector< pair<int, int> > check, edge;
int depth[N+10], sub[N+10];
int up[N+10][20], sum[N+10][20];
int tin[N+10], tout[N+10];
vector<int> val[N+10];
int bigchild[N+10], pos[N+10], chain[N+10];
int timer = 1;
void dfs(int v, int par){
tin[v] = timer++;
up[v][0] = par;
for(int to : g[v]){
if(to == par) continue;
depth[to] = depth[v] + 1;
dfs(to, v);
sub[v]+= sub[to];
if(!bigchild[v] or sub[bigchild[v]] < sub[to]){
bigchild[v] = to;
}
}
sub[v] += 1, tout[v] = timer++;
}
int upper(int p, int a){
return (tin[p] <= tin[a] && tout[p] >= tout[a]);
}
int lca(int a, int b){
if(depth[b] < depth[a]) swap(a, b);
int k = depth[b] - depth[a];
for(int i = 0;i < 20; i++){
if(k & (1<<i)) b = up[b][i];
}
if(a == b) return a;
for(int i = 19; i >= 0; i--){
if(up[b][i] != up[a][i]){
a = up[a][i];
b = up[b][i];
}
}
return up[a][0];
}
void dfs2(int v, int par, int head){
pos[v] = timer++;
chain[v] = head;
if(bigchild[v]){
dfs2(bigchild[v], v, head);
}
for(int to : g[v]){
if(to == par || to == bigchild[v]) continue;
dfs2(to, v, to);
}
}
/*
int query(int a, int b){
if(chain[a] > chain[b]) swap(a, b);
int sum = 0;
while(chain[a] != chain[b]){
if(chain[a] > chain[b]) swap(a, b);
int l =pos[chain[b]], r = pos[b];
//sum+= get(l, r, 1, 1, n);
b = up[chain[b]][0];
}
if(chain[a] > chain[b]) swap(a, b);
int l = pos[a], r = pos[b];
//sum+= get(l, r, 1, 1, n);
return sum;
}
*/
int distance(int a, int b){
int lc = lca(a, b);
return (depth[a] + depth[b] - 2*depth[lc]);
}
int checks(int a, int d){
int cnt = 0;
for(int i = 0;i < 20; i++){
if(d & (1<<i)){
cnt+= sum[a][i];
a = up[a][i];
}
}
return cnt;
}
int go_k(int a, int d){
for(int i = 0;i < 20; i++){
if(d & (1<<i)) a = up[a][i];
}
return a;
}
struct node{
vector<int> a, pr;
};
signed main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
int bambo = 1;
for(int i = 1;i < n; i++){
int a, b; cin >> a >> b;
if(a != i or b != a+1) bambo = 0;
edge.push_back({a, b});
g[a].push_back(b);
g[b].push_back(a);
}
dfs(1, 1);
timer = 1;
dfs2(1, 1, 1);
int coins = 0;
for(int i = 0;i < m; i++){
int p, c; cin >> p >> c;
check.push_back({p, c});
int a = edge[p-1].ff, b = edge[p-1].ss;
if(depth[a] < depth[b]) swap(a, b);
//cout << a << " , " << b << " = " << c << '\n';
sum[a][0] += 1;
val[a].push_back(c);
coins = c;
}
for(int j = 1;j < 20; j++){
for(int i = 1;i <= n; i++){
up[i][j] = up[up[i][j-1]][j-1];
sum[i][j] = sum[i][j-1] + sum[up[i][j-1]][j-1];
}
}
if(max({n, m, q}) <= 2000){
while(q--){
int s, t; cin >> s >> t;
int x, y; cin >> x >> y;
int lc = lca(s, t);
vector<pair<int, int> > vec;
int cnt = checks(s, depth[s] - depth[lc]);
cnt+= checks(t, depth[t] - depth[lc]);
while(s != lc){
for(int sa : val[s]) vec.push_back({sa, 1});
s = up[s][0];
}
while(t != lc){
for(int sa : val[t]) vec.push_back({sa, 1});
t = up[t][0];
}
//cout << "ancestor : ";
//cout << lc << "\n";
sort(all(vec), [&](auto A, auto B){
return A.ff < B.ff;
});
for(auto [silver, gold] : vec){
// cout << silver << ' ' << gold << ", ";
if(y >= silver){
y-= silver;
}else{
x-= gold;
}
}
//cout << '\n';
cout << max(-1LL, x) << '\n';
}
return 0;
}else if(!bambo){
while(q--){
int s, t; cin >> s >> t;
int x, y; cin >> x >> y;
int lc = lca(s, t);
int cnt = checks(s, depth[s] - depth[lc]);
cnt+= checks(t, depth[t] - depth[lc]);
cnt-= (y / coins);
x-= max(0LL, cnt);
cout << max(-1LL, x) << '\n';
}
return 0;
}else{
vector<int> p;
vector<pair<int, int> > range(n+1);
for(int i = 1;i <= n; i++){
range[i].ff = p.size();
for(int x : val[i]){
p.push_back(x);
}
range[i].ss = p.size()-1;
}
int sz = p.size();
vector<node> t(4*sz);
auto merge=[&](auto left, auto right){
node res ={{}, {}};
int i = 0, j = 0;
while(i < (int)left.a.size() || j < (int)right.a.size()){
if(i >= (int)left.a.size() && j >= (int)right.a.size()) break;
if(i >= (int)left.a.size()){
res.a.push_back(right.a[j]);
j++;
}else if(j >= (int)right.a.size()){
res.a.push_back(left.a[i]);
i++;
}else{
if(left.a[i] < right.a[j]){
res.a.push_back(left.a[i]);
i++;
}else{
res.a.push_back(right.a[j]);
j++;
}
}
res.pr.push_back((res.pr.empty() ? 0 : res.pr.back()) + res.a.back());
}
return res;
};
auto build=[&](auto build, int v, int vl, int vr)->auto{
if(vl == vr){
t[v] = {{p[vl]}, {p[vl]}};
return;
}
int mid = (vl + vr)>>1;
build(build, v<<1, vl, mid);
build(build, v<<1|1, mid+1, vr);
t[v] = merge(t[v<<1], t[v<<1|1]);
};
node zero = {{}, {}};
auto get=[&](auto get, int l, int r, int v, int vl, int vr)->auto{
if(l > vr or vl > r) return zero;
if(l <= vl && r >= vr) return t[v];
int mid = (vl + vr)>>1;
return merge(get(get, l, r, v<<1, vl, mid), get(get, l, r, v<<1|1, mid+1, vr));
};
auto sum=[&](auto sum, int l, int r, int x, int v, int vl, int vr)->auto{
if(l > vr or vl > r) return 0LL;
if(l <= vl && r >= vr){
int it = upper_bound(all(t[v].a), x) - t[v].a.begin();
it--;
if(it >= 0) return t[v].pr[it];
else return 0LL;
}
int mid = (vl + vr)>>1;
return sum(sum, l, r, x, v<<1, vl, mid) + sum(sum, l, r, x, v<<1|1, mid+1, vr);
};
auto smaller=[&](auto smaller, int l, int r, int x, int v, int vl, int vr)->auto{
if(l > vr or vl > r) return 0LL;
if(l <= vl && r >= vr){
int it = upper_bound(all(t[v].a), x) - t[v].a.begin();
return it;
}
int mid = (vl + vr)>>1;
return smaller(smaller, l, r, x, v<<1, vl, mid) + smaller(smaller, l, r, x, v<<1|1, mid+1, vr);
};
build(build, 1, 0, sz-1);
while(q--){
int s, t; cin >> s >> t;
int x, y; cin >> x >> y;
if(depth[s] < depth[t]) swap(s, t);
int lc = t;
int cnt = checks(s, depth[s] - depth[lc]);
int l = range[go_k(s, depth[s] - depth[lc] - 1)].ff, r = range[s].ss;
int lo = -1, ro = (int)y + 2;
while(lo + 1 < ro){
int mid = (lo + ro)>>1;
if(sum(sum, l, r, mid, 1, 0, sz-1) > y){
ro = mid;
}else lo = mid;
}
cnt-= smaller(smaller, l, r, ro-1, 1, 0, sz-1);
y-= sum(sum, l, r, ro-1, 1, 0, sz-1);
if(ro > 0) cnt-= (y/ro);
x-= cnt;
cout << max(-1LL, x) << '\n';
}
}
return 0;
}
