#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
using namespace std;

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

vector<int> eul, l, g[100005];
int first[100005], k, n, m;
int log[200010], rmq[20][400020];

void citire() {
    fin >> n >> m;
    for(int i = 2; i <= n; i++) {
        int x;
        fin >> x;
        g[x].push_back(i);
    }
}

void dfs(int x, int lev) {
    l.push_back(lev);
    eul.push_back(x);
    first[x] = eul.size()-1;
    for(int i = 0; i < g[x].size(); i++) {
        dfs(g[x][i], lev+1);
        eul.push_back(x);
        l.push_back(lev);
    }
}

void RMQ() {
    k = eul.size();
    rmq[0][1]=1, rmq[0][0]=1;
    for(int i = 2; i <= k; i++) {
        log[i] = log[i>>1]+1;
        rmq[0][i] = i;
    }
    for(int i = 1; (1<<i) <= k; i++)
        for(int j = 0; j + (1<<i)-1<k; j++) {
            rmq[i][j] = rmq[i-1][j];
            if(l[rmq[i-1][j+1<<(i-1)]] < l[rmq[i][j]])
                rmq[i][j] = rmq[i-1][j+1<<(i-1)];
        }
}

int lca(int x, int y) {
    int dif, sol, lg;
    int a = first[x], b = first[y];
    if(a > b)
        swap(a, b);
    dif = b-a+1;
    lg = log[dif];
    sol = rmq[lg][a];
    if(l[sol]>l[rmq[lg][a+dif-(1<<lg)]])
        sol = rmq[lg][a+dif-(1<<lg)];
    return eul[sol];
}

int main() {
    citire();
    dfs(1, 0);
    RMQ();

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