#include <bits/stdc++.h>
#define int long long
#define endl '\n'
using namespace std;
const int N = 1e5 + 5;
const int LG = 18;
int n, m, queries;
pair < int, int > checks[N];
int s[N], t[N], x[N], y[N];
int lca[N];
vector < pair < int, int > > g[N];
pair < int, int > edges[N];
int dep[N];
int up[LG][N];
int tim = 0;
int tin[N], tout[N];
void dfsBuild(int u, int p)
{
tin[u] = ++tim;
for (auto [v, id] : g[u])
{
if (v == p)
{
continue;
}
dep[v] = dep[u] + 1;
up[0][v] = u;
for (int i = 1; i < LG; i++)
{
up[i][v] = up[i - 1][up[i - 1][v]];
}
dfsBuild(v, u);
}
tout[u] = ++tim;
}
int calcLCA(int u, int v)
{
if (dep[u] < dep[v])
{
swap(u, v);
}
int diff = dep[u] - dep[v];
for (int i = 0; i < LG; i++)
{
if ((diff & (1 << i)))
{
u = up[i][u];
diff -= (1 << i);
}
}
if (u == v)
{
return u;
}
for (int i = LG - 1; i >= 0; i--)
{
if (up[i][u] != up[i][v])
{
u = up[i][u];
v = up[i][v];
}
}
return up[0][u];
}
struct Fenwick
{
int bit[2 * N];
void update(int idx, int val)
{
while (idx <= 2 * n)
{
bit[idx] += val;
idx += idx & (-idx);
}
}
int query(int idx)
{
int sum = 0;
while (idx >= 1)
{
sum += bit[idx];
idx -= idx & (-idx);
}
return sum;
}
void clearFenwick()
{
for (int i = 1; i <= 2 * n; i++)
{
bit[i] = 0;
}
}
};
Fenwick silverPath, goldPath;
void updatePath(bool type, int idx, int sign)
{
int u = checks[idx].second;
int silverCoins = checks[idx].first;
if (!type)
{
silverPath.update(tin[u], silverCoins * sign);
silverPath.update(tout[u], -silverCoins * sign);
}
else
{
goldPath.update(tin[u], sign);
goldPath.update(tout[u], -sign);
}
}
int queryPath(bool type, int queryIdx)
{
int st = s[queryIdx];
int fi = t[queryIdx];
if (!type)
{
return silverPath.query(tin[st]) + silverPath.query(tin[fi]) - 2 * silverPath.query(tin[lca[queryIdx]]);
}
return goldPath.query(tin[st]) + goldPath.query(tin[fi]) - 2 * goldPath.query(tin[lca[queryIdx]]);
}
int L[N], R[N];
int ans[N];
vector < int > v[N];
signed main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> queries;
for (int i = 1; i < n; i++)
{
cin >> edges[i].first >> edges[i].second;
g[edges[i].first].push_back({edges[i].second, i});
g[edges[i].second].push_back({edges[i].first, i});
}
dfsBuild(1, 0);
for (int i = 1; i <= m; i++)
{
int p, c;
cin >> p >> c;
if (tin[edges[p].first] < tin[edges[p].second])
{
checks[i] = {c, edges[p].second};
}
else
{
checks[i] = {c, edges[p].first};
}
}
sort(checks + 1, checks + m + 1);
for (int i = 1; i <= queries; i++)
{
cin >> s[i] >> t[i] >> x[i] >> y[i];
lca[i] = calcLCA(s[i], t[i]);
}
for (int i = 1; i <= queries; i++)
{
L[i] = -1, R[i] = m + 1;
ans[i] = -1;
}
for (int i = 1; i <= LG; i++)
{
bool stop = 1;
for (int i = 0; i <= m; i++)
{
v[i].clear();
}
for (int i = 1; i <= queries; i++)
{
if (L[i] <= R[i])
{
v[(L[i] + R[i]) / 2].push_back(i);
stop = 0;
}
}
if (stop)
{
break;
}
goldPath.clearFenwick();
silverPath.clearFenwick();
for (int i = 1; i <= m; i++)
{
updatePath(1, i, +1);
}
for (int mid = 0; mid <= m; mid++)
{
if (mid)
{
updatePath(1, mid, -1);
updatePath(0, mid, +1);
}
for (int id : v[mid])
{
int currSilver = queryPath(0, id);
int currGold = queryPath(1, id);
if (currSilver <= y[id] && currGold <= x[id])
{
ans[id] = x[id] - currGold;
L[id] = mid;
}
else
{
if (currGold > x[id])
{
L[id] = mid;
}
else
{
R[id] = mid;
}
}
}
}
}
for (int i = 1; i <= queries; i++)
{
cout << ans[i] << endl;
}
return 0;
}
