#include <fstream>
#include <vector>
#include <cmath>

using namespace std;

ifstream in("lca.in");
ofstream out("lca.out");
int n, q, cnt;
vector<int> v[100005];
pair<int, int> euler[200005];
int first[100005];
int rmq[20][200005];

void dfs(int node, int nivel)
{
    cnt++;
    euler[cnt] = {node, nivel};

    for(auto it: v[node])
    {
        dfs(it, nivel + 1);

        cnt++;
        euler[cnt] = {node, nivel};
    }
}

int query(int st, int dr)
{
    st = first[st];
    dr = first[dr];

    if(st > dr)
    {
        swap(st, dr);
    }

    int l = log2(dr - st + 1);
    if(euler[rmq[l][st]].second < euler[rmq[l][dr - (1 << l) + 1]].second)
    {
        return euler[rmq[l][st]].first;
    }
    else
    {
        return euler[rmq[l][dr - (1 << l) + 1]].first;
    }
}

int main()
{
    in>>n>>q;

    int x, y;
    for(int i = 2; i<=n; i++)
    {
        in>>x;

        v[x].push_back(i);
    }

    dfs(1, 1);

    for(int i = 1; i<=cnt; i++)
    {
        if(first[euler[i].first] == 0)
        {
            first[euler[i].first] = i;
        }
    }

    int lg = log2(cnt);
    for(int i = 1; i<=cnt; i++)
    {
        rmq[0][i] = i;
    }

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

    while(q--)
    {
        in>>x>>y;

        out<<query(x, y)<<'\n';
    }

    return 0;
}