#include <bits/stdc++.h>
#define ii pair<int, int>
#define fi first
#define se second
using namespace std;
const int N = 1e5 + 5, S = 18;
int n, m, q, timer;
int d[N], heavy[N], chain[N], sz[N], par[N], num[N], ans[N], sp[2 * N][S], g[N][S], c[N], bit[N], f[N], Left[N];
vector <int> ke[N], euler, A, val[N], lis[N];
stack <int> st[N];
void dfs(int u, int pre = 0) {
int mx = 0;
sz[u] = 1; heavy[u] = -1; num[u] = timer++;
euler.push_back(u);
A.push_back(d[u]);
for(int v : ke[u]) if(v != pre) {
sz[u] += sz[v];
par[v] = u; d[v] = d[u] + 1;
dfs(v, u);
euler.push_back(u);
A.push_back(d[u]);
timer++;
if(sz[v] > mx) {
mx = sz[v];
heavy[u] = v;
}
}
}
void dfss(int u, int pre = 0) {
if(u == 1) f[u] = chain[u] = 1;
for(int v : ke[u]) if(v != pre) {
if(v == heavy[u]) {
chain[v] = chain[u];
f[v] = f[u] + 1;
}
else chain[v] = v, f[v] = 1;
dfss(v, u);
}
}
void upd(int x, int v) {
for(; x <= m; x += (x & -x)) bit[x] += v;
}
void upds(int l, int r, int v) {
upd(l, v);
upd(r + 1, -v);
}
int get(int x) {
int ret = 0;
for(; x > 0; x -= (x & -x)) ret += bit[x];
return ret;
}
void solve(int p, int v, int i) {
upds(st[p].top() + 1, i, v);
while (val[p].size() && v > val[p].back()) {
int r = st[p].top(); st[p].pop();
upds(st[p].top() + 1, r, v - val[p].back());
val[p].pop_back();
}
st[p].push(i);
val[p].push_back(v);
}
void jump(int i, int u) {
while (u) {
solve(chain[u], f[u], i);
u = par[chain[u]];
}
}
void init(int n) {
for(int i = 0; i < n; i++) sp[i][0] = i;
for(int j = 1; (1 << j) <= n; j++) {
for(int i = 1; i + (1 << j) - 1 < n; i++) {
int o = i + (1 << j - 1);
if(A[sp[i][j - 1]] < A[sp[o][j - 1]]) {
sp[i][j] = sp[i][j - 1];
}
else sp[i][j] = sp[o][j - 1];
}
}
}
int lca(int u, int v) {
int l = min(num[u], num[v]), r = max(num[u], num[v]);
int k = log2(r - l + 1);
int i = sp[l][k], j = sp[r - (1 << k) + 1][k];
return (A[i] < A[j]) ? euler[i] : euler[j];
}
void build() {
for(int i = 1; i <= m; i++) g[i][0] = c[i];
for(int j = 1; (1 << j) <= m; j++) {
for(int i = 1; i + (1 << j) - 1 <= m; i++) {
g[i][j] = lca(g[i][j - 1], g[i + (1 << j - 1)][j - 1]);
}
}
}
int get(int l, int r) {
int k = log2(r - l + 1);
return lca(g[l][k], g[r - (1 << k) + 1][k]);
}
main () {
cin.tie(0)->sync_with_stdio(0);
if(fopen("task.inp", "r")) {
freopen("task.inp", "r", stdin);
freopen("wa.out", "w", stdout);
}
cin >> n >> m >> q;
for(int i = 1; i <= n; i++) st[i].push(0);
for(int i = 1; i < n; i++) {
int u, v; cin >> u >> v;
ke[u].push_back(v);
ke[v].push_back(u);
}
for(int i = 1; i <= m; i++) cin >> c[i];
for(int i = 1; i <= q; i++) {
int r; cin >> Left[i] >> r;
lis[r].push_back(i);
}
dfs(1);
dfss(1);
init(timer);
build();
for(int i = 1; i <= m; i++) {
jump(i, c[i]);
for(int j : lis[i]) ans[j] = get(Left[j]) - d[(get(Left[j], i))];
}
for(int i = 1; i <= q; i++) cout << ans[i] << "\n";
}
