#include <fstream>
#include <vector>

using namespace std;

const int N = 1e5;
const int L = 16;

int n_e, eul[2*N], nivel[N+1], prima_ap[N+1];
int n, r[L+1][N+1], log2[N+1];
vector <int> fii[N+1];

void dfs_euler(int x)
{
    eul[++n_e] = x;
    prima_ap[x] = n_e;
    for (auto y: fii[x])
    {
        nivel[y] = 1 + nivel[x];
        dfs_euler(y);
        eul[++n_e] = x;
    }
}

void constructie_rmq()
{
    int n_r = 2*n - 1;
    for (int j = 1; j <= n_r; j++)
    {
        r[0][j] = eul[j];
    }
    for (int i = 1; (1 << i) <= n_r; i++)
    {
        for (int j = (1 << i); j <= n_r; j++)
        {
            int p2 = (1 << (i - 1));
            int rez_st = r[i-1][j-p2];
            int rez_dr = r[i-1][j];
            if (nivel[rez_st] <= nivel[rez_dr])
            {
                r[i][j] = rez_st;
            }
            else
            {
                r[i][j] = rez_dr;
            }
        }
    }
    log2[1] = 0;
    for (int i = 2; i <= n_r; i++)
    {
        log2[i] = 1 + log2[i/2];
    }
}

int interogare_rmq(int st, int dr)
{
    int e = log2[dr-st+1];
    int p2 = (1 << e);
    int rez_st = r[e][st+p2-1];
    int rez_dr = r[e][dr];
    if (nivel[rez_st] <= nivel[rez_dr])
    {
        return rez_st;
    }
    return rez_dr;
}

int lca(int x, int y)
{
    int st = prima_ap[x];
    int dr = prima_ap[y];
    if (st > dr)
    {
        swap(st, dr);
    }
    return interogare_rmq(st, dr);
}

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