// #pragma GCC optimize("O3","unroll-loops")
#include <bits/stdc++.h>
using namespace std;
// #define
#define int long long
#define all(v) v.begin(), v.end()
#define fi first
#define se second
#define file "file"
#define __lcm(a, b) a * b / __gcd(a, b)
#define R(x) {cout << x << "\n"; return;}
#define coutf(x) cout << fixed << setprecision(x)
#define inter(a) cout << a << "\n"; fflush(stdout)
mt19937_64 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
// declare
const int N = 1e5;
vector <pair<int,int>> qu[N + 5];
vector <int> ord,g[N + 5], edge[N + 5];
int n, m, q, a[N + 5], b[N + 5], s[N + 5], t[N + 5], x[N + 5], y[N + 5], p[N + 5], c[N + 5];
int idx = 0, l[N + 5], r[N + 5], md[N + 5], valbegin[N + 5], parent[N + 5], sliver[N + 5], gold[N + 5];
struct Fenwick_Tree_Update_Range_Get_Point
{
int FT[N + 5];
void clear()
{
for (int i = 1; i <= N; ++i) FT[i] = 0;
}
void Update(int idx, int val)
{
for (;idx <= N; idx += idx & (-idx)) FT[idx] += val;
}
void UpdateRange(int l, int r, int v)
{
Update(r + 1, -v);
Update(l, v);
}
int Get(int idx)
{
int val = 0;
for (; idx; idx -= idx & (-idx)) val += FT[idx];
return val;
}
} ft1, ft2;
struct Lca_O1{
vector <int> order;
int h[N + 5], pos[N + 5], ST[20][N + 5];
void dfs(int i, int p)
{
order.push_back(i);
pos[i] = order.size();
for (int j : g[i])
if (j != p)
{
h[j] = h[i] + 1;
dfs(j, i);
order.push_back(i);
}
}
int P(int a, int b)
{
return h[a] < h[b] ? a : b;
}
void Build()
{
int sz = order.size();
for (int i = 1; i <= sz; ++i) ST[0][i] = order[i - 1];
for (int i = 1; i < 18; ++i)
if ((1 << i) <= sz)
{
for (int j = 1; j <= sz - (1 << i) + 1; ++j)
ST[i][j] = P(ST[i - 1][j], ST[i - 1][j + (1 << (i - 1))]);
}
}
int lca(int l, int r)
{
l = pos[l], r = pos[r];
if (l > r) swap(l, r);
int bit = __lg(r - l + 1);
return P(ST[bit][l], ST[bit][r - (1 << bit) + 1]);
}
// declare h[1]
} lc;
void dfs(int i, int p)
{
for (pair <int,int> nw : qu[i])
{
int v = nw.first, pos = nw.second;
if (md[pos] < ord[1])
{
sliver[pos] = 0;
gold[pos] += v * ft1.Get(idx);
continue;
}
int l = 1, r = ord.size() - 1;
while (l < r)
{
int mid = l + r >> 1;
if (ord[mid + 1] <= md[pos]) l = mid + 1;
else r = mid;
}
sliver[pos] += v * ft2.Get(l);
// if (pos == 1 && md[1] == 8) cout << i << ' ' << v * ft2.Get(l) << ' ' << sliver[pos] << "\n";
gold[pos] += v * (ft1.Get(idx) - ft1.Get(l));
}
for (int j : g[i])
if (j != p)
{
for (int v : edge[j])
{
ft1.UpdateRange(v, idx, 1);
ft2.UpdateRange(v, idx, valbegin[v]);
}
dfs(j, i);
for (int v : edge[j])
{
ft1.UpdateRange(v, idx, -1);
ft2.UpdateRange(v, idx, -valbegin[v]);
}
}
}
void Solve()
{
cin >> n >> m >> q;
for (int i = 1; i < n; ++i)
{
cin >> a[i] >> b[i];
g[a[i]].push_back(b[i]);
g[b[i]].push_back(a[i]);
}
lc.dfs(1, 0);
lc.Build();
map <int,bool> mp;
map <int,int> cnt;
for (int i = 1; i <= m; ++i)
{
cin >> p[i] >> c[i];
mp[c[i]] = true;
}
ord.push_back(0);
for (pair <int, bool> x : mp)
{
ord.push_back(x.first);
cnt[x.first] = ++idx;
valbegin[idx] = x.first;
}
for (int i = 1; i <= m; ++i)
{
int u = a[p[i]], v = b[p[i]];
if (lc.h[u] < lc.h[v]) swap(u, v);
edge[u].push_back(cnt[c[i]]);
}
// for (int i = 1; i <= n; ++i)
// {
// cout << i << ": ";
// for (int x : edge[i]) cout << x << " ";
// cout << "\n";
// }
for (int i = 1; i <= q; ++i)
{
cin >> s[i] >> t[i] >> x[i] >> y[i];
parent[i] = lc.lca(s[i], t[i]);
l[i] = 0, r[i] = 1e9;
}
while (true)
{
bool ok = true;
for (int i = 1; i <= n; ++i) qu[i].clear();
for (int i = 1; i <= q; ++i)
if (l[i] != r[i])
{
ok = false;
sliver[i] = gold[i] = 0;
md[i] = l[i] + r[i] >> 1;
++md[i];
qu[s[i]].push_back({1, i});
qu[t[i]].push_back({1, i});
qu[parent[i]].push_back({-2, i});
}
if (ok) break;
dfs(1, 0);
for (int i = 1; i <= q; ++i)
if (l[i] != r[i])
{
if (sliver[i] > y[i]) r[i] = md[i] - 1;
else l[i] = md[i];
}
}
for (int i = 1; i <= q; ++i)
{
sliver[i] = gold[i] = 0;
md[i] = l[i];
qu[s[i]].push_back({1, i});
qu[t[i]].push_back({1, i});
qu[parent[i]].push_back({-2, i});
}
dfs(1, 0);
// for (int i = 1; i <= q; ++i) cout << l[i] << ' ' << sliver[i] << ' ' << gold[i] << "\n";
for (int i = 1; i <= q; ++i)
{
int d = (y[i] - sliver[i]) / (l[i] + 1);
if (!gold[i]) d = 0;
gold[i] = x[i] - gold[i];
gold[i] += d;
if (gold[i] < 0) gold[i] = -1;
cout << gold[i] << "\n";
}
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
if (fopen(file ".inp", "r"))
{
freopen (file ".inp", "r", stdin);
freopen (file ".out", "w", stdout);
}
int t = 1;
// cin >> t;
while (t--)
Solve();
cerr << "\nTIME: " << 1000 * clock() / CLOCKS_PER_SEC << "ms.";
}
