#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>

using namespace std;

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

const int N_MAX = 1e5;
const int E_MAX = N_MAX << 2;
const int INF = 0x3f3f3f3f3f3f3f3f;

int n, q, eLen;
int log2[N_MAX + 10], fr[N_MAX + 10];
pair<int, int> rmq[E_MAX][21];
vector<pair<int, int>> e;
vector<vector<int>> adj;

void scan()
{
    in >> n >> q;

    adj.resize(n + 5);

    for(int i = 2; i <= n; i++)
    {
        int x;
        in >> x;
        adj[x].push_back(i);
    }
}

void euler(int node, int depth)
{
    e.emplace_back(node, depth + 1);

    for(auto it: adj[node])
    {
        euler(it, depth + 1);
        e.emplace_back(node, depth + 1);
    }
}

void calcRmq()
{
    for(int i = 0; i < eLen; i++)
        rmq[i][0] = e[i];

    for(int p = 1; (1 << p) <= eLen; p++)
    {
        for(int i = 0; i < eLen; i++)
        {
            if(rmq[i][p - 1].second < rmq[i + (1 << (p - 1))][p - 1].second)
                rmq[i][p] = rmq[i][p - 1];
            else
                rmq[i][p] = rmq[i + (1 << (p - 1))][p - 1];
        }
    }
}

int query(int x, int y)
{
    //cout << x << ' ' << y << '\n';

    int st = min(fr[x], fr[y]), fs = max(fr[x], fr[y]);
    int d = fs - st + 1;

    /*cout << st << ' ' << fs << '\n';
    cout << d << ' ' << log2[d] << '\n';
    cout << rmq[st][log2[d]].first << ' ' << rmq[st][log2[d]].second << '\n';
    cout << rmq[fs - (1 << log2[d]) + 1][log2[d]].first << ' ' << rmq[fs - (1 << log2[d]) + 1][log2[d]].second << "\n\n";*/

    if(rmq[st][log2[d]].second < rmq[fs - (1 << log2[d]) + 1][log2[d]].second)
        return rmq[st][log2[d]].first;

    return rmq[fs - (1 << log2[d]) + 1][log2[d]].first;
}

int main()
{
    scan();

    euler(1, -1);

    eLen = e.size();

    memset(fr, INF, sizeof fr);

    for(int i = 0; i < eLen; i++)
        fr[e[i].first] = min(i, fr[e[i].first]);

    log2[1] = 0;

    for(int i = 2; i <= eLen; i++)
        log2[i] = log2[i / 2] + 1;

    calcRmq();

    /*for(auto it: e)
        cout << it.first << ' ';

    cout << '\n';

    for(auto it: e)
    {
        cout << it.second << ' ';
        if(it.first >= 10)
            cout << ' ';
    }

    cout << "\n\n";*/

    while(q--)
    {
        int x, y;
        in >> x >> y;
        out << query(x, y) << '\n';
    }

    return 0;
}