/// circular
/// patratele
#include <bits/stdc++.h>
using namespace std;

#define MOD 9901
#define NMAX 100010

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

int i, eu[2 * NMAX][20], ord[2 * NMAX], nin[NMAX], nout[NMAX], val[NMAX], m, x, y, n, vf, sum[2 * NMAX], fx, fy, j;
vector<int> v[NMAX];

void up(int poz, int vl)
{
    for (int i = poz; i <= n; i += i & -i)
        sum[i] += vl;
}

int qu(int poz)
{
    int s = 0;
    for (i = poz; i > 0; i -= i & -1)
        s += sum[i];
    return s;
}
void dfs(int x, int t, int lvl)
{
    eu[++vf][0] = x;
    ord[x] = lvl;
    nin[x] = vf;
    up(vf, val[x]);
    for (auto it : v[x])
    {
        if (it != t)
        {
            dfs(it, x, lvl + 1);
            eu[++vf][0] = x;
        }
    }
    nout[x] = vf;
    up(vf + 1, -val[x]);
}

int lca(int st, int dr)
{
    int l = dr - st + 1;
    int ll = log2(l);
    if (ord[eu[st][ll]] < ord[eu[dr - (1 << ll) + 1][ll]])
        return eu[st][ll];
    else
        return eu[dr - (1 << ll) + 1][ll];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    fin >> n >> m;
    //for (i = 1; i <= n; i++)
      //  fin >> val[i];
    for (i = 2; i <= n; i++)
    {
        fin >> x;
        v[x].push_back(i);
        //v[y].push_back(x);
    }
    dfs(1, 0, 0);
    int ln = log2(vf);
    for (i = 1; i <= ln; i++)
        for (j = 1; j <= vf - (1 << i) + 1; j++)
        {
            eu[j][i] = eu[j][i - 1];
            if (ord[eu[j + (1 << (i - 1))][i - 1]] < ord[eu[j][i - 1]])
                eu[j][i] = eu[j + (1 << (i - 1))][i - 1];
        }
    //fin >> m;
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        fx = nin[x];
        fy = nin[y];
        if (fx > fy)
            swap(fx, fy);
        fout << lca(fx, fy) << '\n';
    }
    return 0;
}