#include <bits/stdc++.h>
using namespace std;
#define int long long
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5 + 5;
int n, m, q;
vector<int> g[N];
int bit[N], bit2[N];
int depth[N], tin[N], tout[N], tim = 0, dp[18][N];
vector<array<int, 2> > edges(N), checkpoints(N);
vector<array<int, 8> > queries(N);
// first 4 are queries values, next two left and right pointers for parallel binary search, second last is the answer
// last is the count of checkpoints for each query
struct BIT
{
int bit[N];
void init()
{
for(int i = 0; i < n + 5; i++)
{
bit[i] = 0;
}
}
void update(int pos, int val)
{
if(pos == 0) return;
for(int i = pos; i < n + 5; i += (i & (-i)))
{
bit[i] += val;
}
}
int query(int pos)
{
if(pos == 0) return 0;
int ans = 0;
for(int i = pos; i > 0; i -= (i & (-i)))
{
ans += bit[i];
}
return ans;
}
} cnt, value;
void dfs(int node, int par)
{
dp[0][node] = par;
tin[node] = ++tim;
for(int to: g[node])
{
if(to == par) continue;
depth[to] = depth[node] + 1;
dfs(to, node);
}
tout[node] = tim;
}
int LCA(int u, int v)
{
if(depth[u] < depth[v])
{
swap(u, v);
}
int diff = depth[u] - depth[v];
for(int i = 17; i >= 0; i--)
{
if((1 << i) & diff)
{
u = dp[i][u];
}
}
if(u == v) return u;
for(int i = 17; i >= 0; i--)
{
if(dp[i][v] != dp[i][u])
{
v = dp[i][v];
u = dp[i][u];
}
}
return dp[0][v];
}
void Solve()
{
cin >> n >> m >> q;
for(int i = 1; i < n; i++)
{
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
edges[i] = {u, v};
}
cnt.init();
value.init();
dfs(1, -1);
// for(int i = 1; i <= n; i++)
// {
// cout << "i = " << i << ", " << tin[i] << " " << tout[i] << "\n";
// }
for(int i = 1; i < 18; i++)
{
for(int j = 1; j <= n; j++)
{
dp[i][j] = ((dp[i - 1][j] == -1) ? -1 : dp[i - 1][dp[i - 1][j]]);
}
}
for(int i = 1; i <= m; i++)
{
cin >> checkpoints[i][0] >> checkpoints[i][1];
}
sort(checkpoints.begin() + 1, checkpoints.begin() + 1 + m, [](array<int, 2> a, array<int, 2> b)
{
return a[1] < b[1];
});
for(int i = 1; i <= m; i++)
{
int edge_idx = checkpoints[i][0];
// cout << "edge_idx = " << edge_idx << endl;
int node = (depth[edges[edge_idx][0]] > depth[edges[edge_idx][1]]) ? edges[edge_idx][0] : edges[edge_idx][1];
// cout << "node = " << node << endl;
cnt.update(tin[node], 1);
cnt.update(tout[node] + 1, -1);
// cout << "update(" << tin[node] << ", 1)\n";
// cout << "update(" << tout[node] + 1 << ", -1)\n";
}
// for(int i = 1; i <= n; i++)
// {
// cout << "i = " << i << ", cnt = " << cnt.query(i) << endl;
// }
for(int i = 1; i <= q; i++)
{
cin >> queries[i][0] >> queries[i][1] >> queries[i][2] >> queries[i][3];
queries[i][4] = 0;
queries[i][5] = m;
queries[i][6] = -1;
queries[i][7] = cnt.query(tin[queries[i][0]]) + cnt.query(tin[queries[i][1]]) - 2 * cnt.query(tin[LCA(queries[i][0], queries[i][1])]);
// cout << "LCA = " << LCA(queries[i][0], queries[i][1]) << "\n";
// cout << "queries[i][7] = " << queries[i][7] << "\n";
}
while(true)
{
cnt.init();
value.init();
vector<int> queries_mid[m + 1];
int counter = 0;
for(int i = 1; i <= q; i++)
{
if(queries[i][4] > queries[i][5])
{
counter++;
continue;
}
int mid = (queries[i][4] + queries[i][5]) / 2;
// cout << "query number = " << i << ", middle value = " << mid << "\n";
queries_mid[mid].push_back(i);
}
if(counter == q)
{
break;
}
for(int i = 0; i <= m; i++)
{
for(int j = 0; j < queries_mid[i].size(); j++)
{
int index = queries_mid[i][j];
// cout << "checkpoint number = " << i << ", index = " << index << endl;
int lca = LCA(queries[index][0], queries[index][1]);
int total_value = (value.query(tin[queries[index][0]]) + value.query(tin[queries[index][1]]) - 2 * value.query(tin[lca]));
int total_count = (cnt.query(tin[queries[index][0]]) + cnt.query(tin[queries[index][1]]) - 2 * cnt.query(tin[lca]));
// cout << "total_value = " << total_value << ", total_count = " << total_count << endl;
if(total_value <= queries[index][3])
{
queries[index][6] = (queries[index][2] >= queries[index][7] - total_count) ? (queries[index][2] - (queries[index][7] - total_count)) : (-1);
queries[index][4] = i + 1;
}
else
{
queries[index][5] = i - 1;
}
}
if(i != m)
{
int edge_idx = checkpoints[i + 1][0];
int node = (depth[edges[edge_idx][0]] > depth[edges[edge_idx][1]]) ? edges[edge_idx][0] : edges[edge_idx][1];
// cout << "edge_idx = " << edge_idx << ", node = " << node << "\n";
cnt.update(tin[node], 1);
cnt.update(tout[node] + 1, -1);
value.update(tin[node], checkpoints[i + 1][1]);
value.update(tout[node] + 1, -checkpoints[i + 1][1]);
// for(int j = 1; j <= n; j++)
// {
// cout << "j = " << j << ", cnt = " << cnt.query(j) << endl;
// }
// for(int j = 1; j <= n; j++)
// {
// cout << "j = " << j << ", value = " << value.query(j) << endl;
// }
}
}
}
for(int i = 1; i <= q; i++)
{
cout << queries[i][6] << "\n";
}
}
int32_t main()
{
auto begin = std::chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
for(int i = 1; i <= t; i++)
{
//cout << "Case #" << i << ": ";
Solve();
}
auto end = std::chrono::high_resolution_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
return 0;
}
