#include <bits/stdc++.h>
#define int long long
#define ll long long
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define pb push_back
#define re exit(0);
#define FOR(i, a, b) for(int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, a, b) for(int i = (a), _b = (b); i >= _b; i--)
#define LOOP(a) for(int i = 0, _a = (a); i < _a; i++)
#define left id<<1
#define right id<<1|1
#define _lower(v, x) lower_bound(v.begin(), v.end(), x) - v.begin() + 1
#define ever ;;
using namespace std;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
template<typename T> void chkmin(T &x, T y) {if (y < x) x = y;}
template<typename T> void chkmax(T &x, T y) {if (y > x) x = y;}
const int mod = 1e9 + 7;
void add(int &a, int b) {
a += b;
if (a >= mod) a -= mod;
if (a < 0) a += mod;
}
int _pow(int a, int b) {
int ans = 1;
while (b) {
if (b % 2 == 1) ans = 1ll * ans * a % mod;
a = 1ll * a * a % mod;
b /= 2;
}
return ans;
}
//--------------------------------------------------------------------------------------------------------------------------------------
const int maxn = 2e5;
struct Edge {
int u, v, check_point_count;
};
struct CheckPoint {
int u, v, w;
bool operator< (const CheckPoint &other) const {
return w < other.w;
}
};
struct Que {
int s, t, gold, silver;
};
struct Fenwick_Tree {
int BIT[maxn + 5]; int n;
void init(int _n) {
n = _n;
FOR(i, 0, n + 2) BIT[i] = 0;
}
void update(int pos, int val) {
while (pos <= n) {
BIT[pos] += val;
pos += pos & -pos;
}
}
void update(int l, int r, int val) {
update(l, val);
update(r + 1, -val);
}
int get(int pos) {
int res = 0;
while (pos) {
res += BIT[pos];
pos -= pos & -pos;
}
return res;
}
};
vii adjList[maxn + 5];
bool costed[maxn + 5];
Edge e[maxn + 5]; CheckPoint cp[maxn + 5]; Que query[maxn + 5];
int n, numCheckPoint, numQuery;
vector<int> bucket[maxn + 5];
int l[maxn + 5], r[maxn + 5], silver_road[maxn + 5];
Fenwick_Tree sum_cost, sum_used;
int timeDfs, tin[maxn + 5], tout[maxn + 5], dep[maxn + 5], check_point_dep[maxn + 5], par[maxn + 5][20];
void pre_dfs(int u, int p) {
tin[u] = ++timeDfs;
for (auto [v, check_point_count] : adjList[u]) if (v != p) {
dep[v] = dep[u] + 1;
check_point_dep[v] = check_point_dep[u] + check_point_count;
par[v][0] = u;
for (int i = 1; i <= 18; i++)
par[v][i] = par[par[v][i - 1]][i - 1];
pre_dfs(v, u);
}
tout[u] = timeDfs;
}
int lca(int u, int v) {
if (dep[u] < dep[v]) swap(u, v);
int h = dep[u] - dep[v];
for (int i = 0; i <= 18; i++) if (h >> i & 1) u = par[u][i];
if (u == v) return u;
for (int i = 18; i >= 0; i--) if (par[u][i] != par[v][i]) u = par[u][i], v = par[v][i];
return par[u][0];
}
int check_point_count_on_path(int u, int v) {
return check_point_dep[u] + check_point_dep[v] - 2 * check_point_dep[lca(u, v)];
}
int used_on_path(int u, int v) {
return sum_used.get(tin[u]) + sum_used.get(tin[v]) - 2 * sum_used.get(tin[lca(u, v)]);
}
int cost_on_path(int u, int v) {
return sum_cost.get(tin[u]) + sum_cost.get(tin[v]) - 2 * sum_cost.get(tin[lca(u, v)]);
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
//#define name "mooo"
//if (fopen(name".inp", "r")) {
// freopen(name".inp", "r", stdin);
// freopen(name".out", "w", stdout);
//}
cin >> n >> numCheckPoint >> numQuery;
FOR(i, 1, n - 1) {
int u, v; cin >> u >> v;
e[i] = {u, v, 0};
}
FOR(i, 1, numCheckPoint) {
int idx, w; cin >> idx >> w;
int u = e[idx].u, v = e[idx].v;
e[idx].check_point_count += 1;
cp[i] = {u, v, w};
}
FOR(i, 1, n - 1) {
auto [u, v, check_point_count] = e[i];
adjList[u].pb({v, check_point_count});
adjList[v].pb({u, check_point_count});
}
pre_dfs(1, 0);
FOR(i, 1, numCheckPoint) {
auto& [u, v, w] = cp[i];
if (par[v][0] != u) swap(u, v);
}
sort(cp + 1, cp + numCheckPoint + 1);
FOR(i, 1, numQuery) {
int s, t, gold, silver;
cin >> s >> t >> gold >> silver;
query[i] = {s, t, gold, silver};
}
FOR(i, 1, numQuery)
l[i] = 1, r[i] = numCheckPoint;
bool process = 0;
for(ever) {
process = 0;
FOR(i, 1, numQuery)
if (l[i] <= r[i])
process = 1;
if (!process) break;
//reset stuff
FOR(i, 1, numCheckPoint)
bucket[i].clear();
sum_cost.init(n); sum_used.init(n);
//
FOR(i, 1, numQuery)
if (l[i] <= r[i])
bucket[(l[i] + r[i]) >> 1].pb(i);
for (int bound = 1; bound <= numCheckPoint; bound++) {
int v = cp[bound].v, w = cp[bound].w;
sum_cost.update(tin[v], tout[v], +w);
sum_used.update(tin[v], tout[v], +1);
for (int queryID : bucket[bound]) {
auto [s, t, gold, silver] = query[queryID];
if (cost_on_path(s, t) <= silver)
silver_road[queryID] = used_on_path(s, t), l[queryID] = bound + 1;
else
r[queryID] = bound - 1;
}
}
}
FOR(queryID, 1, numQuery) {
auto [s, t, gold, silver] = query[queryID];
int gold_road = check_point_count_on_path(s, t) - silver_road[queryID];
int res = gold - gold_road;
if (res < 0) res = -1;
cout << res << '\n';
}
return 0;
}
