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

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

void DF( int x, int niv );
int LCA(int x, int y);
void RMQ();

const int SIZE = 100001;

vector<int> v[SIZE];

int n, m;
int cnt;
int E[2*SIZE], niv[2*SIZE], poz[SIZE], log[2*SIZE];
int rmq[2*SIZE][19];

int main()
{
    int x, y;
    is >> n >> m;
    for ( int i = 2; i <= n; ++i )
    {
        is >> x;
        v[x].push_back(i);
    }

    DF(1, 1);

    RMQ();

    for ( int i = 2; i <= cnt; ++i )
        log[i] = log[i/2] + 1;

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

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

void DF(int x, int nv)
{
    cnt++;
    E[cnt] = x, niv[cnt] = nv, poz[x] = cnt;
    for ( int i = 0; i < v[x].size(); ++i )
    {
        DF(v[x][i], nv+1);
        cnt++;
        E[cnt] = x, niv[cnt] = nv;
    }
}

int LCA(int x, int y)
{
    int k;
    int st, dr;
    st = poz[x];
    dr = poz[y];
    if ( st > dr )
        swap(st, dr);
    k = log[dr-st + 1];

    if ( niv[rmq[st][k]] > niv[rmq[dr - (1 << k) + 1][k]] )
        return E[rmq[dr - (1 << k) + 1][k]];
    return E[rmq[st][k]];
}

void RMQ()
{
    for ( int i = 1; i <= cnt; ++i )
        rmq[i][0] = i;

    for ( int j = 1; (1 << j) <= cnt; ++j )
        for ( int i = 1; i + (1 << j) - 1 <= cnt; ++i )
        {
            if ( niv[rmq[i][j-1]] < niv[rmq[i + (1 << (j-1))][j-1]] )
                rmq[i][j] = rmq[i][j-1];
            else
                rmq[i][j] = rmq[i + (1 << (j-1))][j-1];
        }
}