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

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

const int N_max = 100005;
const int Log = 18;

int lst[N_max];
int vf[N_max];
int urm[N_max];
int nr;

int L[N_max];
bool viz[N_max];

int E[2 * N_max - 1], level[2 * N_max - 1];
int K;

int First[N_max];

int rmq[2 * N_max - 1][Log];
int lg[2 * N_max - 1];

int N, Q;

void adauga(int x, int y)
{
    // ADAUGA IN LISTA LUI x PE y

    nr++;
    vf[nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
}

void read()
{
    int i, x;

    in >> N >> Q;

    for(i = 2; i <= N; i++)
    {
        in >> x;
        adauga(x, i);
    }
}

void euler(int x)
{
    int p, y;

    viz[x] = true;

    E[++K] = x;

    if(!First[x]) First[x] = K;

    // PARCURG VECINII y AI LUI x

    p = lst[x];

    while(p != 0)
    {
        y = vf[p];

        if(!viz[y])
        {
            L[y] = 1 + L[x];

            euler(y);

            E[++K] = x;
        }

        p = urm[p];
    }
}

void RMQ()
{
    int i, j;

    for(i = 1; i <= K; i++) level[i] = L[ E[i] ];

    lg[1] = 0;
    for(i = 2; i <= K; i++) lg[i] = lg[i/2] + 1;

    for(i = 1; i <= K; i++) rmq[i][0] = i;

    for(i = 1; i <= K; i++)
        for(j = 1; (1 << j) <= i; j++)
        {
            int k = i - (1 << (j - 1));

            rmq[i][j] = rmq[i][j - 1];

            if(level[ rmq[k][j - 1] ] < level[ rmq[i][j] ])
                rmq[i][j] = rmq[k][j - 1];
        }
}

void query()
{
    int a, b;

    for(int q = 1; q <= Q; q++)
    {
        in >> a >> b;

        a = First[a];
        b = First[b];

        if(a > b) swap(a, b);

        int l = lg[b - a + 1];

        int ans = rmq[b][l];

        if(level[rmq[a + (1 << l) - 1][l]] < level[ans])
                ans = rmq[a + (1 << l) - 1][l];

        out << E[ans] << '\n';
    }
}

int main()
{
    read();
    euler(1);
    RMQ();
    query();

    return 0;
}