#include <iostream>
using namespace std;

const int MAXN = 1005;

int parent[MAXN];
int depth[MAXN];
int adj[MAXN][MAXN];
int n, m;

void dfs(int nod, int parinte) {
    parent[nod] = parinte;
    for (int i = 1; i <= n; ++i) {
        if (adj[nod][i] && i != parinte) {
            depth[i] = depth[nod] + 1;
            dfs(i, 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() {
    cin >> n >> m;
    for (int i = 1; i < n; ++i) {
        int a, b;
        cin >> a >> b;
        adj[a][b] = adj[b][a] = 1;
    }
    depth[1] = 0;
    dfs(1, 0);
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        cout << lca(u, v) << "\n";
    }
    return 0;
}