#include <iostream>
#include <vector>
#include <algorithm>
#define f first
#define s second
#define int long long
using namespace std;
int n, m, q, p[100010][20], cnt, d[100010], ans[100010], vl[100010];
vector<int> edge[100010];
pair<pair<pair<int,int>,int>,pair<int,int>> qry[100010];
pair<int,int> edd[100010], ed[100010], rng[100010], node[400010], idk[100010];
void dfs(int u, int v, int depth) {
p[u][0] = v;
d[u] = depth;
rng[u].f = ++cnt;
for (int i = 1; i < 20; i++) p[u][i] = p[p[u][i-1]][i-1];
for (int i = 0; i < edge[u].size(); i++) if (edge[u][i] != v) dfs(edge[u][i],u,depth+1);
rng[u].s = cnt;
}
int lca(int u, int v) {
if (d[u] < d[v]) swap(u,v);
int i = 19;
while (i >= 0) {
if (d[p[u][i]] >= d[v]) u = p[u][i];
i--;
}
if (u == v) return u;
i = 19;
while (i >= 0) {
if (p[u][i] != p[v][i]) u = p[u][i], v = p[v][i];
i--;
}
return p[u][0];
}
void split(int id) {
node[id*2].f += node[id].f;
node[id*2+1].f += node[id].f;
node[id*2].s += node[id].s;
node[id*2+1].s += node[id].s;
node[id] = {0,0};
}
void update(int id, int x, int y, int l, int r, pair<int,int> val) {
if ((l <= x) && (y <= r)) {
node[id].f += val.f;
node[id].s += val.s;
return;
}
if ((r < x) || (y < l)) return;
int mid = (x+y)/2;
split(id);
update(id*2,x,mid,l,r,val);
update(id*2+1,mid+1,y,l,r,val);
}
pair<int,int> summ(int id, int x, int y, int pos) {
if (x == y) return node[id];
int mid = (x+y)/2;
split(id);
if (pos <= mid) return summ(id*2,x,mid,pos);
else return summ(id*2+1,mid+1,y,pos);
}
pair<int,int> sum(int u) {
return summ(1,1,n,rng[u].f);
}
void solve(int l, int r, vector<int> query) {
vector<int> ll, rr;
if (l == r) {
for (int i = 0; i < query.size(); i++) {
int u = qry[query[i]].f.f.f, v = qry[query[i]].f.f.s, lcaa = qry[query[i]].f.s;
if (qry[query[i]].s.s < sum(u).f+sum(v).f-2*sum(lcaa).f) ll.push_back(query[i]);
else ans[query[i]] = sum(u).s+sum(v).s-2*sum(lcaa).s;
}
for (int i = l; i <= r; i++) update(1,1,n,rng[ed[i].s].f,rng[ed[i].s].s,{-vl[i],1});
for (int i = 0; i < ll.size(); i++) {
int u = qry[ll[i]].f.f.f, v = qry[ll[i]].f.f.s, lcaa = qry[ll[i]].f.s;
ans[ll[i]] = sum(u).s+sum(v).s-2*sum(lcaa).s;
}
for (int i = l; i <= r; i++) update(1,1,n,rng[ed[i].s].f,rng[ed[i].s].s,{vl[i],-1});
return;
}
int mid = (l+r)/2;
for (int i = mid+1; i <= r; i++) update(1,1,n,rng[ed[i].s].f,rng[ed[i].s].s,{-vl[i],1});
for (int i = 0; i < query.size(); i++) {
int u = qry[query[i]].f.f.f, v = qry[query[i]].f.f.s, lcaa = qry[query[i]].f.s;
if (qry[query[i]].s.s < sum(u).f+sum(v).f-2*sum(lcaa).f) ll.push_back(query[i]);
else rr.push_back(query[i]);
}
solve(l,mid,ll);
for (int i = mid+1; i <= r; i++) update(1,1,n,rng[ed[i].s].f,rng[ed[i].s].s,{vl[i],-1});
solve(mid+1,r,rr);
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m >> q;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
edd[i] = {u,v};
edge[u].push_back(v);
edge[v].push_back(u);
}
dfs(1,0,1);
for (int i = 1; i <= m; i++) cin >> idk[i].s >> idk[i].f;
sort(idk+1,idk+m+1);
for (int i = 1; i <= m; i++) {
int u = idk[i].s, v = idk[i].f;
ed[i] = edd[u];
vl[i] = v;
if (d[ed[i].s] < d[ed[i].f]) swap(ed[i].f,ed[i].s);
update(1,1,n,rng[ed[i].s].f,rng[ed[i].s].s,{vl[i],0});
}
for (int i = 1; i <= q; i++) {
cin >> qry[i].f.f.f >> qry[i].f.f.s >> qry[i].s.f >> qry[i].s.s;
qry[i].f.s = lca(qry[i].f.f.f,qry[i].f.f.s);
}
vector<int> query;
for (int i = 1; i <= q; i++) query.push_back(i);
solve(1,m,query);
for (int i = 1; i <= q; i++) cout << max(-1LL,qry[i].s.f-ans[i]) << endl;
}
