#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 5;
int n, m;
vector <int> g[N];
template <typename Graph>
class LCA_module {
    Graph& g;
    vector <int> p, head, d, sz;
    int k, currh;
    void dfs(int u, int par)
    {
        int link = 0;
        sz[u] = 1;
        d[u] = ++currh;
        for(int v : g[u]) if(v != par) {
            dfs(v, u);
            sz[u] += sz[v];
            if(!link || sz[link] < sz[v])
                link = v;
        }
        if(!link) p[u] = ++k;
        else p[u] = p[link];
        for(int v : g[u]) if(v != link && v != par)
            head[p[v]] = u;
        --currh;
    }
public:
    LCA_module(Graph& _g, int n) : g(_g), p(n + 1, 0), head(n + 1, 0), d(n + 1, 0), sz(n + 1, 0), k(0), currh(0) { dfs(1, 0); }
    int lca(int u, int v)
    {
        while(p[u] != p[v]) {
            if(d[head[p[u]]] < d[head[p[v]]]) swap(u, v);
            u = head[p[u]];
        }
        if(d[u] > d[v]) swap(u, v);
        return u;
    }
};

int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    ios_base :: sync_with_stdio(false); cin.tie(nullptr);
    cin >> n >> m;
    for(int i = 2, p; i <= n; i++)
        cin >> p,
        g[p].push_back(i);
    LCA_module <vector <int>[N]> L(g, n);
    for(int t = 1, u, v; t <= m; t++) {
        cin >> u >> v;
        cout << L.lca(u, v) << "\n";
    }
    return 0;
}