#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int ceil_lg(int k)
{
int res = __lg(k);
if (1<<res < k)
res++;
return res;
}
struct SegTree
{
SegTree(int size)
{
int k = 1<<(ceil_lg(size)+1);
arr.resize(k);
lazy.resize(k);
}
void push(int v)
{
arr[v<<1] += lazy[v];
lazy[v<<1] += lazy[v];
arr[(v<<1)+1] += lazy[v];
lazy[(v<<1)+1] += lazy[v];
lazy[v] = 0;
}
void update(int l, int r, ll val, int v = 1, int a = 0, int b = -1)
{
if (b == -1)
b = (arr.size()>>1)-1;
if (b < l || a > r)
return;
else if (a >= l && b <= r)
{
lazy[v] += val;
arr[v] += val;
}
else
{
int mid = (a+b)>>1;
push(v);
update(l, r, val, v<<1, a, mid);
update(l, r, val, (v<<1)+1, mid+1, b);
}
}
ll query(int k, int v = 1, int a = 0, int b = -1)
{
if (b == -1)
b = (arr.size()>>1)-1;
if (b < k || a > k)
return 0;
else if (a == k && b == k)
return arr[v];
else
{
int mid = (a+b)>>1;
push(v);
return query(k, v<<1, a, mid) + query(k, (v<<1)+1, mid+1, b);
}
}
vector<ll> arr;
vector<ll> lazy;
};
vector<vector<int>> g;
vector<int> pre, post;
vector<int> dep;
vector<vector<int>> up;
vector<pair<int, int>> edges;
struct Checkpoint
{
int v;
ll c;
friend bool operator<(Checkpoint const& c1, Checkpoint const& c2)
{
return c1.c < c2.c;
}
};
struct Query
{
int s, t;
ll x, y;
int l, r;
int idx;
friend bool operator<(Query const& q1, Query const& q2)
{
return (q1.l + q1.r + 1)>>1 < (q2.l + q2.r + 1)>>1;
}
};
int lca(int a, int b)
{
if (dep[a] < dep[b])
swap(a, b);
for (int i = up[a].size()-1; i >= 0; i--)
{
int a_ = up[a][i];
if (dep[a_] >= dep[b])
a = a_;
}
if (a == b)
return a;
for (int i = up[a].size()-1; i >= 0; i--)
{
int a_ = up[a][i], b_ = up[b][i];
if (a_ != b_)
{
a = a_;
b = b_;
}
}
return up[a][0];
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
g.resize(n+1);
pre.resize(n+1);
post.resize(n+1);
dep.resize(n+1);
up.resize(n+1, vector<int>(__lg(n)+1));
edges.resize(n-1);
for (int i = 0; i < n-1; i++)
{
int a, b;
cin >> a >> b;
edges[i] = {a, b};
g[a].push_back(b);
g[b].push_back(a);
}
dep[0] = -1;
int time = 0;
function<void(int, int)> dfs = [&](int u, int p) -> void
{
pre[u] = time++;
dep[u] = dep[p] + 1;
up[u][0] = p;
for (int i = 1; i < up[u].size(); i++)
up[u][i] = up[up[u][i-1]][i-1];
for (auto v : g[u])
if (v != p)
dfs(v, u);
post[u] = time;
};
dfs(1, 0);
vector<Checkpoint> checkpoints(m);
for (int i = 0; i < m; i++)
{
int p, c;
cin >> p >> c;
auto[a, b] = edges[p-1];
if (pre[a] < pre[b])
checkpoints[i] = {b, c};
else
checkpoints[i] = {a, c};
}
sort(checkpoints.begin(), checkpoints.end());
vector<Query> queries(q);
for (int i = 0; i < q; i++)
{
cin >> queries[i].s >> queries[i].t >> queries[i].x >> queries[i].y;
queries[i].l = 0;
queries[i].r = m;
queries[i].idx = i;
}
while (true)
{
vector<Query*> cur_queries;
for (auto& q : queries)
if (q.l != q.r)
cur_queries.push_back(&q);
if (cur_queries.empty())
break;
// cout << cur_queries[0]->l << ' ' << cur_queries[0]->r << '\n';
sort(cur_queries.begin(), cur_queries.end(), [](Query* q1, Query* q2) -> bool {return *q1 < *q2;});
int p = 0;
SegTree st(n);
for (int i = 0; i <= m; i++)
{
for (; p < cur_queries.size(); p++)
{
Query& q = *cur_queries[p];
int mid = (q.l + q.r + 1)>>1;
if (mid > i)
break;
int l = lca(q.s, q.t);
ll val = st.query(pre[q.s]) + st.query(pre[q.t]) - (st.query(pre[l])<<1);
if (val <= q.y)
q.l = mid;
else
q.r = mid-1;
}
if (i < m)
{
Checkpoint c = checkpoints[i];
st.update(pre[c.v], post[c.v]-1, c.c);
}
// for (int i = 0; i < n; i++)
// cout << st.query(i) << ' ';
// cout << '\n';
}
}
SegTree st(n);
vector<int> ans(q);
sort(queries.rbegin(), queries.rend());
int p = 0;
for (int i = m; i >= 0; i--)
{
if (i < m)
{
Checkpoint c = checkpoints[i];
st.update(pre[c.v], post[c.v]-1, 1);
}
for (; p < queries.size(); p++)
{
Query q = queries[p];
if (q.l < i)
break;
int l = lca(q.s, q.t);
ans[q.idx] = q.x - (st.query(pre[q.s]) + st.query(pre[q.t]) - (st.query(pre[l])<<1));
}
}
for (int i = 0; i < q; i++)
cout << (ans[i] >= 0 ? ans[i] : -1) << '\n';
}
