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

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

const int NMAX = 1e5+5, LOG = 22;
int n, q, k;
int depth[2*NMAX], nodes[2*NMAX], poz[NMAX], rmq[LOG][NMAX];
vector<int>tree[NMAX];

inline void liniarizare(int node, int level)
{
    nodes[++k] = node;
    depth[k] = level;
    poz[node] = k;
    for(auto itr : tree[node])
    {
        liniarizare(itr, level + 1);
        nodes[++k] = node;
        depth[k] = level;
    }
}

inline void RMQ()
{
    for(int i = 1; i <= k; ++ i)
        rmq[0][i] = i;
    for(int i = 1; i <= k; ++ i)
    {
        for(int j = 1; j <= k ; ++ 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 main()
{
    fin >> n >> q;
    for(int i = 2; i <= n; ++ i)
    {
        int node;
        fin >> node;
        tree[node].push_back(i);
    }

    liniarizare(1, 0);
    RMQ();
    while(q--)
    {
        int a, b;
        fin >> a >> b;
        a = poz[a];
        b = poz[b];
        if(a > b)
            swap(a, b);
        int k = log2(b - a + 1);
        if(depth[rmq[k][a]] < depth[rmq[k][1 + b - (1<<k)]])
        {
            fout << nodes[rmq[k][a]] << '\n';
        }
        else
        {
            fout << nodes[rmq[k][1 + b - (1<<k)]] << '\n';
        }
    }
}