#include <fstream>
#include <climits>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <bitset>
#include <map>
#include <cstring>
#include <algorithm>

#define NMAX 100003 

using namespace std;



ifstream fin("lca.in");
ofstream fout("lca.out");

int n, m, kEuler;
int niv[NMAX];//nivelul fiecarui nod
int primaAp[2 * NMAX];//prima aparitie in nodurile euler
int noduriEuler[2 * NMAX];//vectorul de muchii euler
int rmq[128][2 * NMAX];
int p[2 * NMAX];//precalcularea puterilor de 2

vector<int>graf[NMAX];

void dfs(int nod, int nivel)
{

    primaAp[nod] = ++kEuler;
    niv[nod] = nivel;
    noduriEuler[kEuler] = nod;
    for (int i = 0; i < graf[nod].size(); i++)
    {
        dfs(graf[nod][i], nivel + 1);
        noduriEuler[++kEuler] = nod;

    }

}

void lca(int L, int R)
{
    int lung = R - L + 1;
    int val = p[lung];

    if (niv[rmq[val][L]] < niv[rmq[val][R + 1 - (1 << val)]])
    {
        fout << rmq[val][L] << "\n";
        return;
    }
    fout << rmq[val][R + 1 - (1 << val)] << "\n";
}

int main()
{

    fin >> n >> m;
    for (int i = 2; i <= n; i++)
    {
        int x;
        fin >> x;

        graf[x].push_back(i);
    }

    dfs(1, 1);
    p[1] = 0;
    for (int i = 2; i <= kEuler; i++)
    {
        p[i] = p[i / 2] + 1;
    }


    //aplic rmq pe vectorul de euler
    for (int i = 1; i <= kEuler; i++)
    {
        rmq[0][i] = noduriEuler[i];
    }

    for (int i = 1; (1 << i) <= kEuler; i++)
    {
        int lungSecv = (1 << i);
        for (int j = 1; j + lungSecv <= kEuler; j++)
        {
            int st = j;
            int dr = j + (1 << (i - 1));
            if (niv[rmq[i - 1][st]] < niv[rmq[i - 1][dr]])
            {
                rmq[i][j] = rmq[i - 1][st];
            }
            else {
                rmq[i][j] = rmq[i - 1][dr];
            }
        }
    }

    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        lca(min(primaAp[x], primaAp[y]), max(primaAp[x], primaAp[y]));
    }
    return 0;
}