#include <bits/stdc++.h>
#define NMAX 200000
using namespace std;

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

int n, k, q;
int RMQ[20][NMAX];
int logs[NMAX + 1];
int nivel[NMAX + 1];
int Euler[NMAX + 1];
int pozE[NMAX / 2 + 1];
vector<int> g[NMAX / 2 + 1];

void DFS(int nod, int niv)
{
    Euler[++k] = nod;
    nivel[k] = niv;
    pozE[nod] = k;
    for (int i : g[nod])
    {
        DFS(i, niv + 1);
        Euler[++k] = nod;
        nivel[k] = niv;
    }
}

void ComputeRMQ()
{
    int val;
    for (int i = 1; i <= k; i++)
        RMQ[0][i] = i;
    for (int i = 1; (1 << i) <= n; i++)
        for (int j = 1; j - (1 << i) + 1 <= k; j++)
        {
            val = (1 << (i - 1));
            RMQ[i][j] = RMQ[i - 1][j];
            if (nivel[RMQ[i - 1][j]] > nivel[RMQ[i - 1][j + val]])
                RMQ[i][j] = RMQ[i - 1][j + val];
        }
}

int main()
{
    int ans;
    int x, y, logac;
    fin >> n >> q;
    for (int i = 2; i <= n; i++)
    {
        fin >> x;
        g[x].push_back(i);
    }
    DFS(1, 0);
    for (int i = 2; i <= k; i++)
        logs[i] = logs[i / 2] + 1;
    ComputeRMQ();
 
    for (int i = 1; i <= q; i++)
    {
        fin >> x >> y;
        x = pozE[x];
        y = pozE[y];
        if (x > y)swap(x, y);
        logac = logs[y - x + 1];
        ans = RMQ[logac][x];
        if (nivel[ans] > nivel[RMQ[logac][y - (1 << logac) + 1]])
            ans = RMQ[logac][y - (1 << logac) + 1];
        fout << Euler[ans] << "\n";
    }
    fin.close();
    fout.close();
    return 0;
}