#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

const int MAXN = 1005;

int parent[MAXN];
int depth[MAXN];
vector<int> adj[MAXN];
int n, m;

void dfs(int nod, int parinte) {
    parent[nod] = parinte;
    for (int i = 0; i < adj[nod].size(); ++i) {
        int vecin = adj[nod][i];
        if (vecin != parinte) {
            depth[vecin] = depth[nod] + 1;
            dfs(vecin, nod);
        }
    }
}

int lca(int u, int v) {
    while (depth[u] > depth[v]) u = parent[u];
    while (depth[v] > depth[u]) v = parent[v];
    while (u != v) {
        u = parent[u];
        v = parent[v];
    }
    return u;
}

int main() {
    ifstream in("lca.in");
    ofstream out("lca.out");

    in >> n >> m;
    for (int i = 1; i < n; ++i) {
        int a, b;
        in >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    depth[1] = 0;
    dfs(1, 0);

    for (int i = 0; i < m; ++i) {
        int u, v;
        in >> u >> v;
        out << lca(u, v) << "\n";
    }

    return 0;
}