#include <fstream>
#include <vector>

using namespace std;

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

int nivel[N+1], e[2*N], rmq[L+1][2*N], prima_ap[N+1], log2[2*N], n_e;
vector <int> fii[N+1];

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

void constructie_rmq()
{
    for (int j = 1; j <= n_e; j++)
    {
        rmq[0][j] = e[j];
    }
    for (int i =1; (1 << i) <= n_e; i++)
    {
        for (int j = (1 << i); j <= n_e; j++)
        {
            int p = (1 << (i - 1));
            rmq[i][j] = rmq[i-1][j-p];
            if (nivel[rmq[i-1][j]] < nivel[rmq[i][j]])
            {
                rmq[i][j] = rmq[i-1][j];
            }
        }
    }
    log2[1] = 0;
    for (int i = 2; i <= n_e; i++)
    {
        log2[i] = 1 + log2[i/2];
    }
}

int interogare(int st, int dr)
{
    if (st > dr)
    {
        swap(st, dr);
    }
    int lung = dr - st + 1;
    int log_lung = log2[lung];
    int p_2 = (1 << log_lung);
    int x_st = rmq[log_lung][st+p_2-1];
    int x_dr = rmq[log_lung][dr];
    if (nivel[x_st] < nivel[x_dr])
    {
        return x_st;
    }
    return x_dr;
}

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