#include <bits/stdc++.h> using namespace std; #define POPCOUNT(n) (__builtin_popcountll((n))) #define CLZ(n) (__builtin_clzll((n))) #define CTZ(n) (__builtin_ctzll((n))) #define LOG(n) (63 - __builtin_clzll((n))) #define BIT(n, i) (((n) >> (i)) & 1ll) #define MASK(i) (1ll << (i)) #define FLIP(n, i) ((n) ^ (1ll << (i))) #define ON(n, i) ((n) | MASK(i)) #define OFF(n, i) ((n) & ~MASK(i)) #define Int __int128 #define fi first #define se second typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair<int, int> pii; typedef pair<long long, long long> pll; typedef pair<long long, int> pli; typedef pair<int, long long> pil; typedef vector<pair<int, int>> vii; typedef vector<pair<long long, long long>> vll; typedef vector<pair<long long, int>> vli; typedef vector<pair<int, long long>> vil; template <class T1, class T2> bool maximize(T1 &x, T2 y) { if (x < y) { x = y; return true; } return false; } template <class T1, class T2> bool minimize(T1 &x, T2 y) { if (x > y) { x = y; return true; } return false; } template <class T> void remove_duplicate(vector<T> &ve) { sort (ve.begin(), ve.end()); ve.resize(unique(ve.begin(), ve.end()) - ve.begin()); } mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); long long random(long long l, long long r) { return uniform_int_distribution<long long>(l, r)(rng); } unsigned long long random(unsigned long long l, unsigned long long r) { return uniform_int_distribution<unsigned long long>(l, r)(rng); } template <class T> T random(T r) { return rng() % r; } const int N = 1e5 + 5, LG = 18; const int MOD = 1e9 + 7; const int inf = 1e9; const long long INF = 1e18; int n, m, q, dfsTime = 0; int ver[N], dep[N], cnt[N], cntEdge[N], up[N][LG]; int tin[N], tout[N], low[N], high[N], ans[N]; pii edges[N], checkpoints[N]; vii adj[N]; struct Query { int s, t, x; ll y; Query(int _s = 0, int _t = 0, int _x = 0, ll _y = 0) { s = _s, t = _t, x = _x, y = _y; } } que[N]; void dfs(int u, int fa) { tin[u] = ++dfsTime; for (auto [v, id] : adj[u]) if (v != fa) { ver[id] = v, cnt[v] = cnt[u] + cntEdge[id]; dep[v] = dep[u] + 1, up[v][0] = u; for (int i = 1; i < LG; ++i) up[v][i] = up[up[v][i - 1]][i - 1]; dfs(v, u); } tout[u] = dfsTime; } int lca(int u, int v) { if (dep[u] < dep[v]) swap(u, v); int delta = dep[u] - dep[v]; for (int i = 0; MASK(i) <= delta; ++i) if (BIT(delta, i)) u = up[u][i]; if (u == v) return u; for (int i = LOG(dep[u]); i >= 0; --i) if (up[u][i] != up[v][i]) { u = up[u][i], v = up[v][i]; } return up[u][0]; } struct FenwickTree { using T = long long; vector<T> bit; FenwickTree() {} void resize(int n) { bit.assign(n + 1, 0); } void update(int p, T val) { for (; p < int(bit.size()); p += p & -p) bit[p] += val; } void update(int l, int r, T val) { update(l, val), update(r + 1, -val); } T get(int p) { T ans = 0; for (; p > 0; p -= p & -p) ans += bit[p]; return ans; } } fen_sum, fen_cnt; signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cin >> n >> m >> q; for (int i = 1; i < n; ++i) { int u, v; cin >> u >> v; adj[u].emplace_back(v, i); adj[v].emplace_back(u, i); edges[i] = make_pair(u, v); } for (int i = 1; i <= m; ++i) { int p, c; cin >> p >> c; checkpoints[i] = make_pair(c, p); ++cntEdge[p]; } sort (checkpoints + 1, checkpoints + 1 + m); dfs(1, -1); for (int i = 1; i < n; ++i) { auto &[u, v] = edges[i]; if (u == ver[i]) swap(u, v); // cerr << u << ' ' << v << '\n'; } // cerr << '\n'; for (int i = 1; i <= q; ++i) { int s, t, x; ll y; cin >> s >> t >> x >> y; que[i] = Query(s, t, x, y); low[i] = 1, high[i] = inf; ans[i] = cnt[s] + cnt[t] - 2 * cnt[lca(s, t)]; } while (true) { vii ve; for (int i = 1; i <= q; ++i) if (low[i] <= high[i]) { int mid = (low[i] + high[i]) >> 1; ve.emplace_back(mid, i); } if (ve.empty()) break; sort (ve.begin(), ve.end()); int j = 0; fen_sum.resize(n), fen_cnt.resize(n); for (auto [mid, id] : ve) { while (j < m && checkpoints[j + 1].fi <= mid) { int v = edges[checkpoints[++j].se].se; fen_sum.update(tin[v], tout[v], checkpoints[j].fi); fen_cnt.update(tin[v], tout[v], 1); } auto [s, t, _, y] = que[id]; int p = lca(s, t); ll sum = fen_sum.get(tin[s]) + fen_sum.get(tin[t]) - 2 * fen_sum.get(tin[p]); int cnt = fen_cnt.get(tin[s]) + fen_cnt.get(tin[t]) - 2 * fen_cnt.get(tin[p]); if (sum >= y) { // cerr << "mid " << mid << ' ' << id << ' ' << sum << ' ' << cnt << ' ' << (sum - y + mid - 1) / mid << '\n'; high[id] = mid - 1; ans[id] = cnt - (sum - y + mid - 1) / mid; } else low[id] = mid + 1; } } for (int i = 1; i <= q; ++i) { auto [s, t, x, _] = que[i]; int gold = (cnt[s] + cnt[t] - 2 * cnt[lca(s, t)]) - ans[i]; // cerr << s << ' ' << t << ' ' << lca(s, t) << '\n'; // cerr << dep[s] + dep[t] - 2 * dep[lca(s, t)] << ' ' << ans[i] << '\n'; if (gold <= que[i].x) cout << que[i].x - gold << '\n'; else cout << "-1\n"; } return 0; }