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

using namespace std;

vector<vector<int>> c;
vector<int> p, level;

int lca(int x, int y) {
    if (level[x] < level[y])
        swap(x, y);
    int lg = 18;
    while (level[x] > level[y]) {
        --lg;
        if (c[x][lg] != -1) {
            if (level[c[x][lg]] >= level[y])
                x = c[x][lg];
        }
    }
    //cout << x << ' ' << y << ' ' << lg << '\n';
    if (x == y)
        return x;
    lg = 18;
    while (p[x] != p[y]) {
        --lg;
        //cout << x << ' ' << y << ' ' << lg << '\n';
        if (c[x][lg] != c[y][lg]) {
            x = c[x][lg];
            y = c[y][lg];
        }
    }
    return p[x];
}

void Init() {
    int n = c.size() - 1;
    for (int i = 1;i <= n;++i)
        c[i][0] = p[i];
    for (int j = 1;(1 << j) < n;++j)
        for (int i = 1;i <= n;++i)
            if (level[i] - (1 << j) > 0) {
            c[i][j] = c[c[i][j - 1]][j - 1];
        }

    /*for (int i = 1;i <= n;++i) {
        cout << i << " : ";
        for (int j = 0;j < 5;++j)
            cout << c[i][j] << ' ';
        cout << '\n';
    }*/

}

int findLevel(int root) {
    if (level[root] != -1) return level[root];
    level[root] = findLevel(p[root]) + 1;
    return level[root];
}

int main() {

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

    int n, m;
    fin >> n >> m;
    p.resize(n + 1, -1);
    level.resize(n + 1, -1);
    c.resize(n + 1);
    for (int i = 1;i <= n;++i)
        c[i].resize(19, -1);
    for (int i = 2;i <= n;++i) {
        int x;
        fin >> x;
        p[i] = x;
    }
    level[1] = 1;
    for (int i = 2;i <= n;++i)
        findLevel(i);

    Init();

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

    return 0;
}