#include <bits/stdc++.h>

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

const int NMAX = 100005;
const int LMAX = 20;
vector <int> v[NMAX];
int n,m,k;
int lvl[NMAX],euler[NMAX],dp[LMAX][NMAX],first[NMAX],lg[NMAX];

void dfs(int nod, int l){
    euler[++k] = nod;
    first[nod] = k;
    lvl[nod] = l;
    for(auto it: v[nod])
        if(!lvl[it]){
            dfs(it, l + 1);
            euler[++k] = nod;
        }
}

void buildDP(){
    int i,j;
    for(i = 2 ; i <= k ; i++)
        lg[i] = lg[i / 2] + 1;

    for(i = 1 ; i <= k ; i++)
        dp[0][i] = euler[i];

    for(i = 1 ; i <= lg[k] ; i++)
        for(j = 1 ; j <= k - (1 << i) ; j++){
            dp[i][j]  = dp[i - 1][j];

            if(lvl[dp[i - 1][j + (1 << (i - 1))]]  < lvl[dp[i - 1][j]])
                dp[i][j] = dp[i - 1][j + (1 << (i - 1) ) ];
        }
}

int query(int x, int y){
    x = first[x];
    y = first[y];
    if(x > y)
        swap(x, y);

    int dif = y - x + 1, l = lg[dif];
    if(lvl[dp[l][x]]  < lvl[dp[l][y - (1 << l) + 1]])
        return dp[l][x];
    return dp[l][y - (1 << l) + 1];
}

int main(){
    int i,x,y;
    f >> n >> m;
    for(i = 2 ; i <= n ; i++){
        f >> x;
        v[x].push_back(i);
    }

    lvl[1] = 1;
    dfs(1,1);
    buildDP();

    for(i = 1 ; i <= m ; i++){
        f >> x >> y;
        g << query(x, y) << "\n";
    }

    return 0;
}