#include <bits/stdc++.h>

using namespace std;
vector <int> tour;
vector <int> v[200001];
bitset <200001> viz;
int lvl[200001];
int n;
int rmq[18][200001],logs[200001];
int poz[200001];
void DFS(int nod,int level){
    lvl[nod] = level;
    tour.push_back(nod);
    poz[nod] = tour.size() - 1;
    viz[nod] = 1;
    for(auto x : v[nod]){
        if(!viz[x]){
            DFS(x,level + 1);
            tour.push_back(nod);
            poz[nod] = tour.size() - 1;
        }
    }
}
void compute(){
    int i,j,lung;
    int cop = n;
    n = tour.size() - 1;
    for(i = 1;i < tour.size();i++){
        rmq[0][i] = tour[i];
    }
    for(i = 2;i <= n;i++){
        logs[i] = logs[i/2] + 1;
    }
    for(i = 1;i <= logs[n];i++){
        int lung = 1 << i;
        for(j = 1;j + lung - 1 <= n;j++){
            int a = rmq[i-1][j];
            int b = rmq[i-1][j + lung/2];
            if(lvl[a] > lvl[b])
                rmq[i][j] = b;
            else
                rmq[i][j] = a;
        }
    }
    n = cop;
}
int getmin(int a,int b){
    a = poz[a];
    b = poz[b];
    if(a > b)
        swap(a,b);
    int cv = logs[b - a + 1];
    int lung = 1 << cv;
    int x = rmq[cv][a];
    int y = rmq[cv][b - lung + 1];
    if(lvl[x] > lvl[y])
        return y;
    return x;
}
int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    int m,i,x;
    cin >> n >> m;
    tour.push_back(0);
    for(i = 2;i <= n;i++){
        cin >> x;
        if(x != i){
            v[x].push_back(i);
            v[i].push_back(x);
        }
    }
    for(i = 1;i <= n;i++){
        if(!viz[i]){
            DFS(i,1);
        }
    }
    compute();
    while(m--){
        int y;
        cin >> x >> y;
        cout << getmin(x,y) << "\n";
    }
    return 0;
}