#include <bits/stdc++.h>
    
using namespace std;
    
typedef long long ll;
const int  N = 1e5 + 12, MOD = (int)1e9 + 7;

const int l = 17;
int n, m, q, tin[N], tout[N], timer, dep[N], s[N], up[N][18];
vector<int> g[N];

void dfs(int v, int pr = 1) {
    tin[v] = ++timer;
    s[v] = 1;
    up[v][0] = pr;
    for(int i = 1; i < l; ++i) {
        up[v][i] = up[up[v][i - 1]][i - 1];
    }
    for(int to:g[v]) {
        if(to != pr) {
            dep[to] = dep[v] + 1;
            dfs(to, v);
            s[v] += s[to];
        }
    }
    tout[v] = ++timer;
}
bool is(int v, int u) {
    return (tin[v] <= tin[u] && tout[v] >= tout[u]);
}
int lca(int v, int u) {
    if(is(v, u)) return v;
    if(is(u, v)) return u;
    for(int i = l - 1; i >= 0; i--) {
        if(!is(up[v][i], u)) {
            v = up[v][i];
        }
    }
    return up[v][0];
}
int  c[N];
pair<int, int> t[N * 4];
void build(int v = 1, int tl = 1, int tr = m - 1) {
    if(tl == tr) {
        int x = lca(c[tl], c[tl + 1]);
        t[v] = {dep[x], x};
    } else {
        int tm = (tl + tr) >> 1;
        build(v + v, tl, tm);
        build(v + v + 1, tm + 1, tr);
        t[v] = min(t[v + v], t[v + v + 1]);
    }
}
const int inf = 1e9;
pair<int, int> get(int l, int r, int v = 1, int tl = 1, int tr = m - 1) {
    if(l > r || tl > r || l > tr) return {inf, inf};
    if(tl >= l && tr <= r) return t[v];
    int tm = (tl + tr) >> 1;
    return min(get(l, r, v + v, tl, tm), get(l, r, v + v + 1, tm + 1, tr));
}
void test() {
    cin >> n >> m >> q;
    for(int i = 1; i <= n - 1; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    dep[1] = 1;
    dfs(1);
    for(int i = 1; i <= m; i++) {
        cin >> c[i];
    }
    build();
    for(int i = 1; i <= q; i++) {
        int l, r;
        cin >> l >> r;
        vector<int> t;
        for(int i = l; i <= r; i++) {
            t.push_back(c[i]);
        }
        sort(t.begin(), t.end(), [&](int x, int y) {
            return tin[x] < tin[y];
        });
        int res = dep[t[0]], v = c[l];
        if(l < r) {
            v = get(l, r - 1).second;
        }
        for(int i = 1; i < (int)t.size(); i++) {
            res += dep[t[i]] - dep[lca(t[i - 1], t[i])];
        }
        cout << res - dep[v] + 1 << '\n';
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); 
    
    int t = 1; 
    // cin >> t;
    
    while(t--) 
        test();
    return 0;
}