#include <bits/stdc++.h>
using namespace std;

#define ll long long

#define N 300

struct equation {
    bool c[N];
    int v;
    int n;

    struct query {
        int u, v;
    } q;

    equation(): n(0), v(0) {
        memset(c, 0, sizeof(c));
        v = 0;
    };
    equation(int n, int i, int qu, int qv): n(n), v(0) { 
        memset(c, 0, sizeof(c));
        q.u = qu;
        q.v = qv;
    }

    inline equation& operator^=(equation& x) {
        assert(n == x.n);
        for (int i = 0; i < n; ++ i) c[i] ^= x.c[i];
        v ^= x.v;
        return *this;
    } 
};

int solve_eqts(vector<equation>& eqts, int n) {
    int res = 0;
    for (int i = 0; i < n; ++ i) {
        for (int j = i; j < eqts.size(); ++ j) {
            if (eqts[j].c[i]) {
                swap(eqts[i], eqts[j]);
                ++ res;
                break;
            }
        }
        for (int j = 0; j < eqts.size(); ++ j) {
            if (i != j && eqts[j].c[i]) eqts[j] ^= eqts[i];
        }
    }
    return res;
}

vector<int> G[N];
int dep[N], f[N];

void dfs(int u, int fa, int d) {
    f[u] = fa;
    dep[u] = d;
    for (auto v : G[u]) if (v != fa) dfs(v, u, d+1);
}

int get_eqt(int u, int v, equation& e) {
    e.c[u-1] = e.c[v-1] = 1;
    if (dep[u] > dep[v]) return 1 + get_eqt(f[u], v, e);
    if (dep[u] < dep[v]) return 1 + get_eqt(u, f[v], e);
    if (u != v) return 2 + get_eqt(f[u], f[v], e);
    return 1;
}
 
int main() {
#ifdef TEST
    freopen("zz.in", "r+", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, k; cin >> n >> k;
    for (int i = 1; i <= n-1; ++ i) {
        int u, v; cin >> u >> v;
        G[u].emplace_back(v);
        G[v].emplace_back(u);
    }
    dfs(1, 1, 0);

    vector<equation> eqts;
    eqts.emplace_back(n, -1, 0, 0);
    get_eqt(1, 1, eqts.back());
    for (int i = 1; i <= n; ++ i) {
        for (int j = i+1; j <= n; ++ j) {
            eqts.emplace_back(n, -1, i, j);
            if (get_eqt(i, j, eqts.back()) != k+1) {
                eqts.pop_back();
            }
        }
    }

    int res = solve_eqts(eqts, n);
    if (res == n) {
        eqts.erase(eqts.begin()+n, eqts.end());

        cout << "YES\n? " << n-1 << ' ';
        for (int i = 1; i < n; ++ i) cout << eqts[i].q.u << ' ' << eqts[i].q.v << " \n"[i==n-1];
        cout.flush();

        for (int i = 1; i < n; ++ i) {
            memset(eqts[i].c, 0, sizeof(eqts[i].c));
            get_eqt(eqts[i].q.u, eqts[i].q.v, eqts[i]);
            cin >> eqts[i].v;
        }
        solve_eqts(eqts, n);

        cout << "! ";
        for (int i = 1; i < n; ++ i) cout << eqts[i].v << " \n"[i==n-1];
        cout.flush();
    } else {
        cout << "NO\n";
        cout.flush();
    }
}