#include <fstream>
#include <vector>

using namespace std;

const int N = 1e5;
const int L = 17;

int rmq[L+1][2*N+1], e[2*N+1], poz[N+1], niv[N+1], log[2*N+1], n, ne;
vector <int> fii[N+1];

void dfs_e(int x)
{
    e[++ne] = x;
    poz[x] = ne;
    for (auto y: fii[x])
    {
        niv[y] = 1 + niv[x];
        dfs_e(y);
        e[++ne] = x;
    }
}

int lca(int x, int y)
{
    int st = poz[x], dr = poz[y];
    if (st > dr)
    {
        swap(st, dr);
    }
    int e = log[dr-st+1];
    int p = (1 << e);
    x = rmq[e][st+p-1];
    y = rmq[e][dr];
    if (niv[y] < niv[x])
    {
        x = y;
    }
    return x;
}

void calcul_rmq()
{
    for (int i = 1; i <= ne; i++)
    {
        rmq[0][i] = e[i];
    }
    for (int e = 1; (1 << e) <= ne; e++)
    {
        for (int i = (1 << e); i <= ne; i++)
        {
            rmq[e][i] = rmq[e-1][i];
            int p = (1 << (e-1));
            if (niv[rmq[e-1][i-p]] < niv[rmq[e][i]])
            {
                rmq[e][i] = rmq[e-1][i-p];
            }
        }
    }
    log[1] = 0;
    for (int i = 2; i <= ne; i++)
    {
        log[i] = 1 + log[i/2];
    }
}

int main()
{
    ifstream in("lca.in");
    ofstream out("lca.out");
    int nq;
    in >> n >> nq;
    for (int i = 2; i <= n; i++)
    {
        int t;
        in >> t;
        fii[t].push_back(i);
    }
    dfs_e(1);
    calcul_rmq();
    for (int i = 0; i < nq; i++)
    {
        int x, y;
        in >> x >> y;
        out << lca(x, y) << "\n";
    }
    in.close();
    out.close();
    return 0;
}