#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 20;
const int LMAX = 17;

int n, q;
vector<int> g[NMAX];
int dad[NMAX], lvl[NMAX];
int timeIn[NMAX], euler[NMAX * 2];
int cnt;
int l2[NMAX * 2];
int rmq[2 * NMAX][LMAX + 1];

void dfs(int nod)
{
    lvl[nod] = lvl[dad[nod]] + 1;
    timeIn[nod] = ++cnt;
    euler[cnt] = nod;
    for(auto it : g[nod])
    {
        dfs(it);
        euler[++cnt] = nod;
    }
}

void buildRmq()
{
    for(int i = 1; i <= cnt; i++)
        rmq[i][0] = euler[i];
    for(int l = 1; l <= LMAX; l++)
        for(int i = 1; i + (1 << l) - 1 <= cnt; i++)
        {
            if(lvl[rmq[i][l - 1]] < lvl[rmq[i + (1 << (l - 1))][l - 1]])
                rmq[i][l] = rmq[i][l - 1];
            else rmq[i][l] = rmq[i + (1 << (l - 1))][l - 1];
        }
}

int query(int st, int dr)
{
    int l = l2[dr - st + 1];
    if(lvl[rmq[st][l]] < lvl[rmq[dr - (1 << l) + 1][l]])
        return rmq[st][l];
    return rmq[dr - (1 << l) + 1][l];
}

int main()
{
    fin >> n >> q;
    for(int i = 2; i <= n; i++)
    {
        fin >> dad[i];
        g[dad[i]].push_back(i);
    }
    for(int i = 2; i <= 2 * n; i++)
        l2[i] = l2[i >> 1] + 1;
    dfs(1);
    buildRmq();
    while(q--)
    {
        int x, y;
        fin >> x >> y;
        if(timeIn[x] > timeIn[y])
            swap(x, y);
        fout << query(timeIn[x], timeIn[y]) << '\n';
    }
    return 0;
}