//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,abm,popcnt,mmx")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;
typedef long double ldb;
typedef complex<double> cd;

constexpr ll INF64 = 9'000'000'000'000'000'000, INF32 = 2'000'000'000, MOD = 1'000'000'007;
constexpr db PI = acos(-1);
constexpr bool IS_FILE = false, IS_TEST_CASES = false;

random_device rd;
mt19937 rnd32(rd());
mt19937_64 rnd64(rd());

template<typename T>
bool assign_max(T& a, T b) {
        if (b > a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
bool assign_min(T& a, T b) {
        if (b < a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
T square(T a) {
        return a * a;
}

template<>
struct std::hash<pair<ll, ll>> {
        ll operator() (pair<ll, ll> p) const {
                return ((__int128)p.first * MOD + p.second) % INF64;
        }
};

void solve() {
        ll n;
        cin >> n;
        string s;
        cin >> s;
        vector<vector<ll>> tree(n);
        for (ll i = 1; i < n; i++) {
                ll a, b;
                cin >> a >> b;
                a--;
                b--;
                tree[a].push_back(b);
                tree[b].push_back(a);
        }
        vector<ll> mc(n + 1, INF32);
        for (ll i = 0; i < (1 << n); i++) {
                string now(n, '0');
                ll ncol = 0;
                for (ll j = 0; j < n; j++) {
                        if ((i >> j) & 1) {
                                now[j] = '1';
                                ncol++;
                        }
                }
                for (ll j = 0; j <= n; j++) {
                        if (now == s) {
                                assign_min(mc[j], ncol);
                        }
                        string nnow = now;
                        for (ll k = 0; k < n; k++) {
                                if (now[k] == '1') {
                                        for (auto l : tree[k]) {
                                                nnow[l] = '1';
                                        }
                                }
                        }
                        now = nnow;
                }
        }
        ll q;
        cin >> q;
        for (ll i = 0; i < q; i++) {
                ll k;
                cin >> k;
                cout << (mc[k] == INF32 ? -1 : mc[k]) << '\n';
        }
}

int main() {
        if (IS_FILE) {
                freopen("", "r", stdin);
                freopen("", "w", stdout);
        }
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
        ll t = 1;
        if (IS_TEST_CASES) {
                cin >> t;
        }
        for (ll i = 0; i < t; i++) {
                solve();
        }
}