#include <fstream>
#include <iostream>
#include <vector>
#define DIM 100010

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

vector<int> L[DIM];
int E[2*DIM], N[2*DIM], F[DIM], lg[2*DIM];
int D[19][2*DIM];

int n, m, k, x, y, z, j;

void euler(int nod, int niv)
{
    E[++k] = nod;
    N[k] = niv;
    F[nod] = k;
    for(int i = 0; i < L[nod].size(); i++)
    {
        euler(L[nod][i], niv + 1);
        E[++k] = nod;
        N[k] = niv;
    }
}

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

    euler(1, 1);

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

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

    for(i = 1; (1 << i) <= k; i++)
    {
        for (j=1;j<=k;j++)
        {
            D[i][j] = D[i-1][j];
            if ((j+(1<<(i-1)) <= k) && (N[ D[i][j] ] > N[ D[i-1][j+(1<<(i-1))] ]))
                D[i][j] = D[i-1][j+(1<<(i-1))];
        }
    }

    for(i = 1; i <= m; i++)
    {
        fin >> x >> y;
        x = F[x];
        y = F[y];

        if (x > y)
        {
            int aux = x;
            x = y;
            y = aux;
        }

        z = lg[y-x+1];
        if ( N[ D[z][x] ] < N[  D[z][y-(1<<z)+1] ] ) {
            fout<<E[D[z][x]]<<"\n";
        } else {
            fout<<E[D[z][y-(1<<z)+1]]<<"\n";
        }
    }
    return 0;
}