#include <bits/stdc++.h>
#define NMAX  100002
#define LGMAX 7
using namespace std;
int n,x,y,m,euler[NMAX*2],k,niv[NMAX],rmq[LGMAX][NMAX],e[NMAX*2];
vector<int> v[NMAX];
pair<int, int> ap[NMAX];

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

void dfs(int nod, int tata){
    euler[++k] = nod;
    ap[nod] = {k, k};
    for(int vecin: v[nod]){
        if(niv[vecin] == 0){
            niv[vecin] = 1+niv[nod];
            dfs(vecin, nod);
            euler[++k] = nod;
            ap[nod].second = k;
        }
    }
}

int lca(int a, int b){
    int st = ap[a].first;
    int dr = ap[b].second;
    if(st > dr){
        swap(a, b);
        st = ap[a].first;
        dr = ap[b].second;
    }
    int len = dr-st+1;
    int log = e[len];
    int x = rmq[log][st], y = rmq[log][dr-(1<<log)+1];
    if(niv[x] < niv[y]){
        return x;
    }
    return y;
}

int main()
{
    fin >> n >> m;
    for(int i = 2; i <= n; i++){
        fin >> x;
        v[x].push_back(i);
        v[i].push_back(x);
    }
    niv[1] = 1;
    dfs(1, -1);
    e[1] = 0;
    for(int i = 1; i <= k; i++){
        if(i > 1)
            e[i] = e[(i>>1)]+1;
        rmq[0][i] = euler[i];
    }
    for(int i = 1; i <= e[k]; i++){
        for(int j = 1; j <= k; j++){
            rmq[i][j] = rmq[i-1][j];
            if(j+(1<<(i-1)) <= k){
                if(niv[rmq[i-1][j+(1<<(i-1))]] < niv[rmq[i][j]]){
                    rmq[i][j] = rmq[i-1][j+(1<<(i-1))];
                }
            }else{
            }
        }
    }
    while(m--){
        fin >> x >> y;
        fout << lca(x, y) << "\n";
    }
    return 0;
}