#include <bits/stdc++.h>
#define in "lca.in"
#define out "lca.out"
using namespace std;
ifstream fin(in);
ofstream fout(out);

int rmq[22][400005];
int E[400005],k;
int niv[400005],poz[100003];
int a[100003],n;
int P[100003];
vector <int> L[100003];

void Euler(int nod, int nivel)
{
    E[++k] = nod;
    niv[k] = nivel;
    poz[nod] = k;
    for(auto i : L[nod])
    {
        Euler(i,nivel+1);
        E[++k] = nod;
        niv[k] = nivel;
    }
}

void Puteri()
{
    int i;

    P[1] = 0;
    for(i = 2; i <= k; i++)
        P[i] = 1 + P[i/2];
}

void RMQ()
{
    int i,N,j,x,y;

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

    N = P[k];
    for(i = 1; i <= N; i++)
        for(j = 1; j <= k - (1 << i) + 1; j++)
        {
            x = niv[rmq[i-1][j]];
            y = niv[rmq[i-1][j+(1<<(i-1))]];

            if(x < y) rmq[i][j] = rmq[i-1][j];
            else rmq[i][j] = rmq[i-1][j + (1<<(i-1))];
        }
}

int main()
{
    int i,j,x,y,len,Q;

    fin >> n >> Q;
    for(i = 2; i <= n; i++)
    {
        fin >> x;
        L[x].push_back(i);
    }

    Euler(1,1);
    Puteri();
    RMQ();

    while(Q--)
    {
        fin >> x >> y;
        x = poz[x];
        y = poz[y];

        if(x > y) swap(x,y);

        len = P[y-x+1];
        i = rmq[len][x];
        j = rmq[len][y - (1<<len) + 1];

        if(niv[i] < niv[j]) fout << E[i] << "\n";
        else fout << E[j] << "\n";
    }

    fin.close();
    fout.close();
    return 0;
}