#include <bits/stdc++.h>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int NMAX = 1e5 + 1, LOG = 18;
vector<int> adj[NMAX];
int n, q, rmq[LOG][NMAX], depth[NMAX], euler[NMAX], cnt = 0, timp_in[NMAX];

void dfs(int nod, int dep)
{
    depth[cnt] = dep;
    euler[cnt] = nod;
    timp_in[nod] = cnt++;
    for(int vec : adj[nod])
    {
        dfs(vec, dep + 1);
        depth[cnt] = dep;
        euler[cnt] = nod;
        cnt++;
    }
}

void build()
{
    for(int i = 0; i < cnt; i++)
        rmq[0][i] = i;
    for(int i = 1; i < LOG; i++)
    {
        for(int j = 1; j + (1 << i) - 1 < cnt; j++)
        {
            if(depth[rmq[i - 1][j]] < depth[rmq[i - 1][j + (1 << (i - 1))]])
                rmq[i][j] = rmq[i - 1][j];
            else
                rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
        }
    }
}

int query(int st, int dr)
{
    int len = dr - st + 1;
    int e = 31 - __builtin_clz(len);
    if(depth[rmq[e][st]] < depth[rmq[e][dr - (1 << e) + 1]])
        return euler[rmq[e][st]];
    else
        return euler[rmq[e][dr - (1 << e) + 1]];
}

int main()
{
    fin >> n >> q;
    for(int i = 2; i <= n; i++)
    {
        int tata;
        fin >> tata;
        adj[tata].push_back(i);
    }
    dfs(1, 0);
    build();

    while(q--)
    {
        int u, v;
        fin >> u >> v;
        int st = min(timp_in[u], timp_in[v]), dr = max(timp_in[u], timp_in[v]);
        fout << query(st, dr) << "\n";
    }

    return 0;
}