#include <bits/stdc++.h>
using namespace std;
template <typename Fn>
class segment_tree {
int n;
vector<int> seg;
Fn merge;
int idt;
public:
segment_tree(int n, const Fn &merge, int idt) : merge(merge), idt(idt), n(n), seg(2 * n, idt) {}
void set(int i, int x) {
for (seg[i += n] = x, i >>= 1; i > 0; i >>= 1) {
seg[i] = merge(seg[2 * i], seg[2 * i + 1]);
}
}
int query(int l, int r) {
int ans = idt;
for (l += n, r += n + 1; l < r; l >>= 1, r >>= 1) {
if (l & 1) ans = merge(ans, seg[l++]);
if (r & 1) ans = merge(ans, seg[--r]);
}
return ans;
}
};
const int inf = 1e9;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> adj(n + 1);
for (int i = 0, u, v; i < n - 1; ++i) {
cin >> u >> v;
adj[u].push_back(v), adj[v].push_back(u);
}
vector<int> c(m);
for (int &i : c) {
cin >> i;
}
segment_tree st_min(m, [&](int a, int b) { return min(a, b); }, inf);
segment_tree st_max(m, [&](int a, int b) { return max(a, b); }, -inf);
for (int i = 0; i < m; ++i) {
st_min.set(i, c[i]);
st_max.set(i, c[i]);
}
while (q--) {
int l, r;
cin >> l >> r;
--l, --r;
cout << st_max.query(l, r) - st_min.query(l, r) + 1 << '\n';
}
}
