#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5e5 + 25;
int in[MAXN], out[MAXN], depth[MAXN];
pair <int, int> sparse[__lg(MAXN)][MAXN];
vector <int> adj[MAXN];
int n, m, q;
int cnt = 0;
void dfs (int pos, int par, int dep = 1) {
depth[pos] = dep;
sparse[0][++cnt] = {dep, pos};
assert(cnt < MAXN);
in[pos] = cnt;
for (auto j : adj[pos]) {
if (j != par) {
dfs(j, pos, dep + 1);
sparse[0][++cnt] = {dep, pos};
assert(cnt < MAXN);
}
}
out[pos] = dep;
}
int query (int l, int r) {
if (l > r) swap(l, r);
if (l == r) return sparse[0][l].second;
int x = __lg(r - l + 1);
return min(sparse[x][l], sparse[x][r - (1 << x) + 1]).second;
}
int arr[MAXN];
int main () {
cin >> n >> m >> q;
for (int i = 1; i < n; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
dfs(1, -1);
for (int i = 1; i <= __lg(cnt); i++) {
for (int j = 1; j <= cnt; j++) {
sparse[i][j] = min(sparse[i - 1][j], sparse[i - 1][j + (1 << (i - 1))]);
}
}
for (int i = 1; i <= m; i++) cin >> arr[i];
for (int i = 1; i <= q; i++) {
int l, r;
cin >> l >> r;
vector <int> g;
for (int j = l; j <= r; j++) g.push_back(arr[j]);
sort(g.begin(), g.end(), [&] (int a, int b) {
return in[a] < in[b];
});
int ans = depth[g[0]], lca = g[0];
for (int j = 1; j < (int)g.size(); j++) {
ans += depth[g[j]] - depth[query(in[g[j]], in[g[j - 1]])];
lca = query(in[lca], in[g[j]]);
}
ans -= depth[lca]; ans++;
cout << ans << '\n';
}
}
