#include <iostream>
#include <vector>
#define pii pair<int, int>
#define mk make_pair
#define MAX 100005
#define NMAX 18
using namespace std;

int n, m, x, y, e[2 * MAX], esiz, pos[MAX], lvl[MAX];
vector<int> l[MAX];
pii rmq[NMAX][2 * MAX];
int log[2 * MAX];

void euler(int x, int d){
    pos[x] = esiz;
    rmq[0][esiz] = mk(x, d);
    e[esiz++] = x;
    lvl[x] = d;

    for(int i = 0; i < l[x].size(); ++i){
        euler(l[x][i], d + 1);
        rmq[0][esiz] = mk(x, d);
        e[esiz++] = x;
    }
}

void constrRMQ(){
    for(int i = 1; i <= log[esiz]; ++i)
        for(int j = 0; j <= esiz - (1<<i); ++j)
            if(rmq[i - 1][j].second < rmq[i - 1][j + (1<<(i - 1))].second)
                rmq[i][j] = rmq[i - 1][j];
            else
                rmq[i][j] = rmq[i - 1][j + (1<<(i - 1))];
}

int lca(int x, int y){
    if(x == y)
        return x;
    int px = pos[x], py = pos[y];
    if(px > py)
        swap(px, py);

    int d = log[py - px + 1];
    if(rmq[d][px].second < rmq[d][py - (1<<d) + 1].second)
        return rmq[d][px].first;
    else
        return rmq[d][py - (1<<d) + 1].first;
}

int main(){
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    cin >> n >> m;
    for(int i = 2; i <= n; ++i){
        cin >> x;
        l[x].push_back(i);
    }

    euler(1, 0);

    for(int i = 2; i <= esiz; ++i)
        log[i] = log[i / 2] + 1;
    constrRMQ();

    for(int i = 0; i < m; ++i){
        cin >> x >> y;
        cout << lca(x, y) << "\n";
    }
    return 0;
}