#include <bits/stdc++.h>

using namespace std;

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

vector <int> lAd[100001];
int euler[200001], prPoz[100001], niv[100001], n, m, k;
int dp[18][200001], l2[200001];

void eulerDFS (int u, int p)
{
    euler[++k] = u;
    prPoz[u] = k;
    niv[u] = 1 + niv[p];
    for (auto n : lAd[u])
    {
        if(n != p)
        {
            eulerDFS(n, u);
            euler[++k] = u;
        }
    }
}

int lca (int x, int y)
{
    int p1 = prPoz[x];
    int p2 = prPoz[y];
    if(p1 > p2)
        swap(p1, p2);
    int lg = p2 - p1 + 1, logaritm = l2[lg], p = (1 << logaritm);
    int a = dp[logaritm][p1];
    int b = dp[logaritm][p2 - p + 1];
    if(niv[a] < niv[b])
        return a;
    else
        return b;
}

int main()
{
    fin >> n >> m;
    for (int i = 2; i <= n; ++i)
    {
        int p;
        fin >> p;
        lAd[i].push_back(p);
        lAd[p].push_back(i);
    }
    eulerDFS(1, 0);
    for (int i = 1; i <= k; ++i)
        dp[0][i] = euler[i];
    for (int i = 1; (1 << i) <= k; ++i)
        for (int j = 1; j <= k; ++j)
        {
            dp[i][j] = dp[i - 1][j];
            if(j + (1 << (i - 1)) <= k &&
               niv[dp[i][j]] > niv[dp[i - 1][j + (1 << (i - 1))]])
                dp[i][j] = dp[i - 1][j + (1 << (i - 1))];
        }
    l2[1] = 0;
    for (int i = 2; i <= k; ++i)
        l2[i] = 1 + l2[i / 2];
    while(m --)
    {
        int x, y;
        fin >> x >> y;
        fout << lca (x, y) << "\n";
    }
}