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

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

vector <int> v[100001];
int k, h[200001];
int p[200001], rmq[19][200001]; //rmq[i][j] = nodul cu nivelul minim din secventa de lungime 1<<i care porneste din j
int ap[100001];
int log2[100001];

void dfs(int r, int niv)
{
    k++;
    p[k] = r;
    h[k] = niv;
    ap[r] = k;
    for (int i = 0; i<v[r].size(); i++)
    {
        dfs(v[r][i], niv+1);
        k++;
        p[k] = r;
        h[k] = niv;
    }
}

int main()
{
    int n, i, m, x, j, d, rasp;
    fin >> n >> m;
    for (i = 2; i<=n; i++)
    {
        fin >> x;
        v[x].push_back(i);
        log2[i] = 1 + log2[i>>1];
    }
    dfs(1, 0);
    for (i = 1; i<=k; i++)
        rmq[0][i] = i;
    for (i = 1; (1<<i) <= k; i++)
        for (j = 1; j<=k-(1<<i)+1; j++)
        {
            rmq[i][j] = rmq[i-1][j];
            if (h[rmq[i-1][j+(1<<(i-1))]] < h[rmq[i][j]])
                rmq[i][j] = rmq[i-1][j+(1<<(i-1))];
        }
    for (i = 1; i<=m; i++)
    {
        fin >> x >> j;
        x = ap[x];
        j = ap[j];
        if (x > j)
            swap(x, j);
        d = log2[j-x+1];
        rasp = rmq[d][x];
        if (h[rmq[d][j-(1<<d)+1]] < h[rasp])
            rasp = rmq[d][j-(1<<d)+1];
        fout << p[rasp] << '\n';
    }
    return 0;
}