#include <fstream>
#include <vector>

using namespace std;

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

int rmq[18][400005];
int E[400005], k, niv[400005], poz[100005];
int a[100005], n;
int P[100005];
vector <int> L[100005];

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;
    }
}

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

    Euler(1, 1);
    for(int i = 2; i <= k; ++i)
        P[i] = 1 + P[i/2];
    /// rmq:
    for(int i = 1; i <= k; ++i) rmq[0][i] = i;
    int N = P[k], x, y;
    for(int i = 1; i <= N; ++i)
        for(int 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))];
        }

    while(Q--)
    {
        fin >> x >> y;
        x = poz[x]; y = poz[y];
        if(x > y) swap(x, y);
        N = P[y-x+1];
        int i = rmq[N][x];
        int j = rmq[N][y-(1<<N)+1];
        if(niv[i] < niv[j]) fout << E[i] << '\n';
        else fout << E[j] << '\n';
    }
    fin.close(); fout.close();
    return 0;
}