#include <bits/stdc++.h>
#define int long long
using namespace std;
static const int MAXN = 1000000;
int N, M, Q;
vector<int> adj[MAXN+5];
pair<int,int> checkpoint[MAXN+5];
pair<int,int> edgeList[MAXN+5];
int log2table[2*MAXN+5];
int euler[2*MAXN+5], timer = 0;
int st[2*MAXN+5][22], depthArr[MAXN+5];
int firstPos[MAXN+5];
int tour1 = 0, in1[MAXN+5], out1[MAXN+5];
int LCA(int u, int v) {
int l = firstPos[u], r = firstPos[v];
if (l > r) swap(l, r);
int k = log2table[r - l + 1];
int a = st[l][k], b = st[r - (1<<k) + 1][k];
return depthArr[a] < depthArr[b] ? a : b;
}
void dfs(int u, int p, int d) {
depthArr[u] = d;
firstPos[u] = ++timer;
euler[timer] = u;
for (int v: adj[u]) {
if (v == p) continue;
dfs(v, u, d+1);
euler[++timer] = u;
}
in1[u] = ++tour1;
out1[u] = tour1;
}
void buildLCA() {
for (int i = 1; i <= timer; i++) {
st[i][0] = euler[i];
}
int K = log2table[timer];
for (int j = 1; j <= K; j++) {
for (int i = 1; i + (1<<j) - 1 <= timer; i++) {
int x = st[i][j-1], y = st[i + (1<<(j-1))][j-1];
st[i][j] = depthArr[x] < depthArr[y] ? x : y;
}
}
}
struct SegTree {
vector<int> t, lz;
int n;
void init(int _n) {
n = _n;
t.assign(4*n+4, 0);
lz.assign(4*n+4, 0);
}
void apply(int id, int val) {
t[id] += val;
lz[id] += val;
}
void push(int id) {
if (lz[id]) {
apply(id<<1, lz[id]);
apply(id<<1|1, lz[id]);
lz[id] = 0;
}
}
void update(int id, int l, int r, int ql, int qr, int v) {
if (qr < l || r < ql) return;
if (ql <= l && r <= qr) {
apply(id, v);
return;
}
int mid = (l+r)>>1;
push(id);
update(id<<1, l, mid, ql, qr, v);
update(id<<1|1, mid+1, r, ql, qr, v);
t[id] = t[id<<1] + t[id<<1|1];
}
int queryPoint(int id, int l, int r, int pos) {
if (l == r) return t[id];
int mid = (l+r)>>1;
push(id);
return pos <= mid
? queryPoint(id<<1, l, mid, pos)
: queryPoint(id<<1|1, mid+1, r, pos);
}
};
SegTree segW, segS;
struct Query {
int u, v, G, Sneed;
};
Query Qs[MAXN+5];
int lo[MAXN+5], hi[MAXN+5], ansCp[MAXN+5], usedSilver[MAXN+5];
vector<int> bucket[MAXN+5];
int calcSilver(int u, int v) {
int su = segW.queryPoint(1,1,tour1,in1[u]);
int sv = segW.queryPoint(1,1,tour1,in1[v]);
int sl = segW.queryPoint(1,1,tour1,in1[LCA(u,v)]);
return su + sv - 2*sl;
}
int calcCount(int u, int v) {
int su = segS.queryPoint(1,1,tour1,in1[u]);
int sv = segS.queryPoint(1,1,tour1,in1[v]);
int sl = segS.queryPoint(1,1,tour1,in1[LCA(u,v)]);
return su + sv - 2*sl;
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> N >> M >> Q;
for(int i=1;i<N;i++){
int A,B; cin>>A>>B;
adj[A].push_back(B);
adj[B].push_back(A);
edgeList[i] = {A,B};
}
for(int i=1;i<=M;i++){
cin>>checkpoint[i].first>>checkpoint[i].second;
}
log2table[1]=0;
for(int i=2;i<=2*N;i++){
log2table[i] = log2table[i>>1] + 1;
}
dfs(1,0,0);
buildLCA();
for(int i=1;i<=Q;i++){
cin>>Qs[i].u>>Qs[i].v>>Qs[i].G>>Qs[i].Sneed;
lo[i]=1; hi[i]=M; ansCp[i]=0; usedSilver[i]=0;
}
bool cont=true;
while(cont){
cont=false;
for(int i=1;i<=M;i++) bucket[i].clear();
for(int i=1;i<=Q;i++){
if(lo[i]<=hi[i]){
cont=true;
bucket[(lo[i]+hi[i])>>1].push_back(i);
}
}
if(!cont) break;
segW.init(tour1);
segS.init(tour1);
for(int i=1;i<=M;i++){
int ei = checkpoint[i].first;
auto [u,v] = edgeList[ei];
if(depthArr[u] < depthArr[v]) swap(u,v);
segW.update(1,1,tour1, in1[u], out1[u], checkpoint[i].second);
segS.update(1,1,tour1, in1[u], out1[u], 1);
for(int qi: bucket[i]){
int needS = calcSilver(Qs[qi].u, Qs[qi].v);
if(needS <= Qs[qi].Sneed){
ansCp[qi] = i;
usedSilver[qi] = needS;
lo[qi] = i+1;
} else {
hi[qi] = i-1;
}
}
}
}
for(int i=1;i<=Q;i++){
if(ansCp[i]==0){
cout << -1 << "\n";
} else {
int silverUsed = usedSilver[i];
int needGold = max(0LL, silverUsed - Qs[i].Sneed);
cout << (Qs[i].G - needGold) << "\n";
}
}
return 0;
}
