#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n, tt;

struct Iris {
    int nod, adan;
};

class LCA {
private:
    int n;
    vector<vector<int>> muchii;
    vector<Iris> euler; ///{nod, adancime nod}
    vector<int> first; ///prima aparitie
    vector<vector<int>> rmq;
    vector<int> expo;
public:
    void init(int _n) {
        n = _n;
        muchii.assign(n + 1, {});
        euler.clear();
        first.assign(n + 1, -1);
        rmq.clear();
        expo.assign(n + 1, 0);
    }
    void add_edge(int x, int y) {
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    void dfs(int nod, int parent, int adancime) {
        first[nod] = euler.size();
        euler.push_back({nod, adancime});
        for(int vecin : muchii[nod]) {
            if(vecin != parent) {
                dfs(vecin, nod, adancime + 1);
                euler.push_back({nod, adancime});
            }
        }
    }
    void build(int root = 1) {
        dfs(root, -1, 0);
        int m = euler.size();
        expo.assign(m + 1, 0);
        expo[1] = 0;
        for(int i=2; i<=m; i++) expo[i] = 1 + expo[i / 2];
        int maxP2 = expo[m] + 1;
        rmq.assign(maxP2 + 1, vector<int>(m + 1, 0));
        for(int i=0; i<m; i++) rmq[0][i] = i;
        for(int p=1, px=2; p<maxP2; p++, px *= 2) {
            for(int i=0; i+px<m; i++) {
                int x = rmq[p - 1][i];
                int y = rmq[p - 1][i + (1 << (p - 1))];
                rmq[p][i] = (euler[x].adan < euler[y].adan ? x : y);
            }
        }
    }
    int queryRmq(int st, int dr) {
        int putere = expo[dr - st + 1];
        int lung = (1 << putere);
        int x = rmq[putere][st];
        int y = rmq[putere][dr - lung + 1];
        return (euler[x].adan < euler[y].adan ? x : y);
    }
    int lca(int u, int v) {
        int st = first[u];
        int dr = first[v];
        if(st > dr) swap(st, dr);
        int index = queryRmq(st, dr);
        return euler[index].nod;
    }
};
LCA lca;

int main()
{
    fin >> n >> tt;
    lca.init(n);
    for(int i=2; i<=n; i++) {
        int tata; fin >> tata;
        lca.add_edge(i, tata);
    }
    lca.build();
    while(tt--) {
        int x, y; fin >> x >> y;
        fout << lca.lca(x, y) << '\n';
    }

    return 0;
}