#include <iostream>
#include <fstream>
#include <vector>
#include <math.h>

using namespace std;

vector<vector<int>> c;
vector<int> level, euler, first;
vector<vector<int>> g;

int lca(int x, int y) {
    if (first[x] > first[y])
        swap(x, y);
    int lg = 0;
    //cout << first[x] << ' ' << first[y] << '\n';
    while ((1 << (lg + 1)) < first[y] - first[x] + 1) ++lg;
    //cout << lg << '\n';
    
    x = c[first[x]][lg];
    y = c[first[y] - (1<<lg) + 1][lg];
    //cout << x << ' ' << y << '\n';
    if (level[x] < level[y])
        return x;
    return y;
}

void dfs(int u, int l) {
    level[u] = l;
    euler.push_back(u);
    first[u] = euler.size() - 1;
    for (auto v : g[u]) {
        dfs(v, l + 1);
        euler.push_back(u);
    }
}

void Init() {
    for (int i = 0;i < c.size();++i)
        c[i][0] = euler[i];
    for(int j=1;(1<<j)<c.size();++j)
        for (int i = 0;i + (1 << j) < c.size();++i) {
            int x = c[i][j - 1], y = c[i + (1 << (j - 1))][j - 1];
            if (level[x] < level[y])
                c[i][j] = x;
            else c[i][j] = y;
        }

    /*for (int i = 0;i < c.size();++i) {
        for (int j = 0;j < 5;++j)
            cout << c[i][j] << ' ';
        cout << '\n';
    }*/
}

int main() {

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

    int n, m;
    fin >> n >> m;
    g.resize(n + 1);
    level.resize(n + 1, -1);
    first.resize(n + 1, -1);

    for (int i = 2;i <= n;++i) {
        int x;
        fin >> x;
        g[x].push_back(i);
    }
    dfs(1, 1);

    /*for (auto x : euler)
        cout << x << ' ';
    cout << '\n';*/

    c.resize(euler.size());
    for (int i = 0;i < c.size();++i)
        c[i].resize(20, -1);

    Init();


    while (m--) {
        int x, y;
        fin >> x >> y;
        fout << lca(x, y) << '\n';
    }

    return 0;
}