#include <bits/stdc++.h>
using namespace std;
const int MAXN =  15 + 1e5;
const int LOGMAX = 25;
int euler[2 * MAXN - 1], first[MAXN], dist[MAXN], rmq[2 * MAXN - 1][LOGMAX], last, lg[2 * MAXN - 1];
vector <int> g[MAXN];
void initializare(){
    for(int i = 0; i < last; ++i)
        rmq[i][0] = euler[i];
    for(int i = 2; i <= last; ++i)
        lg[i] = lg[i / 2] + 1;
}
void RangeALG(){
    for(int j = 1; (1 << j) < last; ++j){
        for(int i = 0; i + ( 1 << (j - 1) ) - 1 < last; ++i){
            if(dist[rmq[i][j - 1]] < dist[rmq[i + ( 1 << (j - 1))][j - 1]])
                rmq[i][j] = rmq[i][j - 1];
            else rmq[i][j] = rmq[i + (1 << (j - 1))][j - 1];
        }
    }
}
void dfs(int node, int papa){
    euler[++last] = node;
    dist[node] = dist[papa] + 1;
    first[node] = last;
    for(auto y : g[node]) {
        if(y != papa){
            dfs(y, node);
            euler[++last] = node;
        }
    }
}
int query(int st, int dr){
    st = first[st];
    dr = first[dr];
    if(st > dr) swap(st, dr);
    int logaritm = lg[dr - st + 1];
    if(dist[rmq[st][logaritm]] < dist[rmq[dr - (1 << logaritm) + 1][logaritm]])
        return rmq[st][logaritm];
    return rmq[dr - (1 << logaritm) + 1][logaritm];
}
ifstream fin("lca.in");
ofstream fout("lca.out");
int main(){
    int n, m;
    fin >> n >> m;
    for(int i = 0; i < n - 1; ++i){
        int x;
        fin >> x;
        g[x].push_back(i + 2);
    }
    dist[0] = -1;
    dfs(1, 0);
    initializare();
    RangeALG();
    for(int i = 1; i <= m; ++i){
        int x, y;
        fin >> x >> y;
        fout << query(x, y) << '\n';
    }
    return 0;
}