#include <bits/stdc++.h>
using namespace std;
#define file "bai4"
//#define int long long
#define ll long long
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define mask(i) (1 << i)
const int N = 1e5, inf = 1e9, K = __lg(N);
void MAX(int &a, int b) { a = max(a, b); }
void MIN(int &a, int b) { a = min(a, b); }
int n, m, q, curchain, Time;
int h[N + 2], up[N + 2][K + 2], lg[N + 2], ans[N + 2],
cnt[N + 2], in[N + 2], ID[N + 2], head[N + 2], sz[N + 2],
par[N + 2], s[N + 2], t[N + 2], L[N + 2], R[N + 2];
bool ok[N + 2];
ll dp[N + 2], all[N + 2], fw[N + 2], X[N + 2], Y[N + 2], sum[N + 2],
remain[N + 2];
vector<int> g[N + 2], val[N + 2];
vector<pii> ed, smt[N + 2];
void dfs(int u, int p)
{
h[u] = h[p] + 1;
sz[u] = 1;
for (int v : g[u])
if (v != p)
{
up[v][0] = u;
for (int j = 1; j <= K; j++)
{
if (up[v][j - 1] == 0) break;
up[v][j] = up[up[v][j - 1]][j - 1];
}
dfs(v, u);
sz[u] += sz[v];
}
}
void hld(int u, int p)
{
if (head[curchain] == 0) head[curchain] = u;
ID[u] = curchain;
in[u] = ++Time;
par[u] = p;
int big = 0;
for (int v : g[u])
if (v != p && sz[v] > sz[big]) big = v;
if (big > 0) hld(big, u);
for (int v : g[u])
if (v != p && v != big)
{
curchain++;
hld(v, u);
}
}
void dfs2(int u, int p)
{
for (int v : g[u])
if (v != p) dp[v] += dp[u], dfs2(v, u);
}
int upk(int u, int k)
{
for (int j = 0; mask(j) <= k; j++)
if (k & mask(j)) u = up[u][j];
return u;
}
void lca(int u, int v, int id)
{
if (h[u] < h[v]) swap(u, v);
int U = u, V = v;
int k = h[u] - h[v];
u = upk(u, k);
if (u == v)
{
int w = u;
u = U; v = V;
if (v == w) swap(u, v);
all[id] = dp[v] - dp[w];
u = upk(v, h[v] - h[w] - 1);
smt[id].pb({v, u});
}
else
{
k = lg[h[u]];
for (int j = k; j >= 0; j--)
if (up[u][j] != up[v][j]) u = up[u][j], v = up[v][j];
smt[id].pb({U, u});
smt[id].pb({V, v});
u = up[u][0];
all[id] = dp[U] + dp[V] - 2 * dp[u];
}
}
void update(int u, int x)
{
while (u <= n) fw[u] += x, u += u & -u;
}
ll get(int u)
{
ll ans = 0;
while (u > 0) ans += fw[u], u -= u & -u;
return ans;
}
ll GET(int l, int r)
{
return get(r) - get(l - 1);
}
ll getpath(int u, int v)
{
ll res = 0;
while (ID[u] > ID[v])
{
res += GET(in[head[ID[u]]], in[u]);
u = par[head[ID[u]]];
}
res += GET(in[v], in[u]);
return res;
}
ll getqry(int id)
{
ll res = 0;
for (pii &x : smt[id]) res += getpath(x.fi, x.se);
return res;
}
int lcaslow(int u, int v, int id)
{
ll sum = 0;
vector<int> cur;
if (h[u] < h[v]) swap(u, v);
while (h[u] > h[v])
{
for (int x : val[u]) cur.pb(x), sum += x;
u = up[u][0];
}
while (u != v)
{
for (int x : val[u]) cur.pb(x), sum += x;
for (int x : val[v]) cur.pb(x), sum += x;
u = up[u][0]; v = up[v][0];
}
sort(cur.begin(), cur.end(), greater<int>());
if (sum <= Y[id]) return X[id];
for (int i = 0; i < sz(cur); i++)
{
if (i + 1 > X[id]) break;
sum -= cur[i];
if (sum <= Y[id]) return X[id] - (i + 1);
}
return -1;
}
void Sub1(vector<pii> &f)
{
for (int i = 1; i <= m; i++)
{
int id, x;
cin >> id >> x;
id--;
if (h[f[id].fi] > h[f[id].se]) val[f[id].fi].pb(x);
else val[f[id].se].pb(x);
}
for (int i = 1; i <= q; i++)
{
cin >> s[i] >> t[i] >> X[i] >> Y[i];
cout << lcaslow(s[i], t[i], i) << "\n";
}
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (fopen(file".inp", "r"))
{
freopen(file".inp", "r", stdin);
freopen(file".out", "w", stdout);
}
cin >> n >> m >> q;
vector<pii> f;
for (int i = 1; i < n; i++)
{
int u, v;
cin >> u >> v;
f.pb({u, v});
g[u].pb(v);
g[v].pb(u);
}
for (int i = 2; i <= n; i++) lg[i] = lg[i / 2] + 1;
dfs(1, 0);
// if (max({n, m, q}) <= 2e3) return Sub1(f), 0;
hld(1, 0);
for (int i = 1; i <= m; i++)
{
int id, x;
cin >> id >> x;
pii cur;
cur.fi = x;
id--;
if (h[f[id].fi] > h[f[id].se]) cur.se = f[id].fi;
else cur.se = f[id].se;
dp[cur.se] += x;
ed.pb(cur);
}
dfs2(1, 0);
for (int i = 1; i <= q; i++)
{
cin >> s[i] >> t[i] >> X[i] >> Y[i];
L[i] = 1; R[i] = inf + 1;
lca(s[i], t[i], i);
}
sort(ed.begin(), ed.end(), greater<pii>());
// for (pii &f : ed) cout << f.fi << " " << f.se << "\n";
bool run = 1;
while (run)
{
run = 0;
vector<pii> qry;
for (int i = 1; i <= q; i++)
if (L[i] <= R[i])
{
qry.pb({(L[i] + R[i]) / 2, i});
run = 1;
}
sort(qry.begin(), qry.end(), greater<pii>());
for (int i = 1; i <= n; i++) fw[i] = 0;
int pos = 0;
for (pii &f : qry)
{
int id = f.se;
while (pos < sz(ed) && ed[pos].fi >= f.fi)
{
update(in[ed[pos].se], ed[pos].fi);
pos++;
}
ll cur = getqry(id);
if (all[id] - cur <= Y[id])
{
ok[id] = 1;
sum[id] = cur;
remain[id] = all[id] - cur;
}
else ok[id] = 0;
}
for (int i = 1; i <= q; i++)
if (L[i] <= R[i])
{
if (ok[i])
{
ans[i] = (L[i] + R[i]) / 2;
L[i] = (L[i] + R[i]) / 2 + 1;
}
else R[i] = (L[i] + R[i]) / 2 - 1;
}
}
vector<pii> qry;
for (int i = 1; i <= q; i++) qry.pb({ans[i], i});
sort(qry.begin(), qry.end(), greater<pii>());
for (int i = 1; i <= n; i++) fw[i] = 0;
int pos = 0;
for (pii &f : qry)
{
int id = f.se;
while (pos < sz(ed) && ed[pos].fi >= f.fi)
{
update(in[ed[pos].se], 1);
pos++;
}
ll cur = getqry(id);
cnt[id] = cur;
}
for (int i = 1; i <= q; i++)
{
ll delta = (Y[i] - remain[i]) / ans[i];
if (delta >= cnt[i]) cout << X[i] << "\n";
else
{
cnt[i] -= delta;
if (cnt[i] > X[i]) cout << -1 << "\n";
else cout << X[i] - cnt[i] << "\n";
}
}
}
