#include <fstream>
#include <vector>
using namespace std;

ifstream is("lca.in");
ofstream os("lca.out");

const int MaxN = 100001;

vector<int> E, Lvl, Pos, log2;
vector<vector<int> > G;
int r[2 * MaxN][20];
int n, m, nr;

void Read();
void Df(int node, int lvl);
void RMQ();
int Lca(int x, int y);

int main()
{
    Read();
    Df(1, 1);
    RMQ();

 //   for ( const int& p : Lvl )
     //   os << p << ' ' ;

    int x, y;
    for ( int i = 1; i <= m; ++i )
    {
        is >> x >> y;
        os << Lca(x, y) << '\n';
    }

    is.close();
    os.close();
    return 0;
}


void Read()
{
    is >> n >> m;
    E = vector<int>(2 * n + 2);
    Lvl = vector<int>(2 * n + 2);
    Pos = vector<int>(n + 1);
    log2 = vector<int>(2 * n + 2);
    G = vector<vector<int> >(n + 1);

    int node;
    for ( int i = 2; i <= n; ++i )
    {
        is >> node;
        G[node].push_back(i);
    }

    for ( int i = 2; i <= 2 * n - 1; ++i )
        log2[i] = log2[i / 2] + 1;
}

void Df(int node, int lvl)
{
    nr++;
    E[nr] = node;
    Lvl[nr] = lvl;
    Pos[node] = nr;
    for ( const auto& g : G[node] )
    {
        Df(g, lvl + 1);
        nr++;
        E[nr] = node;
        Lvl[nr] = lvl;
    }
}

void RMQ()
{
    for ( int i = 1; i <= 2 * n - 1; ++i )
        r[i][0] = i;

    for ( int j = 1; (1 << j) <= 2 * n - 1; ++j )
        for ( int i = 1; i + (1 << j) <= 2 * n; ++i )
            if ( Lvl[r[i][j - 1]] < Lvl[r[i + (1 << (j - 1))][j - 1]] )
                r[i][j] = r[i][j - 1];
            else
                r[i][j] = r[i + (1 << (j - 1))][j - 1];
}
int Lca(int x, int y)
{
    x = Pos[x];
    y = Pos[y];
    if ( x > y )
        swap(x, y);

    int k = log2[y - x + 1];

    if ( Lvl[r[x][k]] < Lvl[r[y - (1 << k) + 1][k]] )
        return  E[r[x][k]];
    return E[r[y - (1 << k) + 1][k]];
}