#include <fstream>
#include <vector>
#include <cmath>
#define DIM 100002
#define ff first
#define ss second

using namespace std;

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

int n, q, t[DIM], k, put[DIM], x, y, l;

pair<int, int> euler[2 * DIM], poz[DIM], d[100][DIM];

vector<int> arb[DIM];

void dfs(int nod, int niv){
    euler[++k].ss = nod;
    euler[k].ff = niv;
    poz[nod].ff = k;
    for(int i = 0; i < arb[nod].size(); ++ i){
        dfs(arb[nod][i], niv + 1);
        euler[++k].ss = nod;
        euler[k].ff = niv;
    }
    poz[nod].ss = k;
}

int main()
{
    f>>n>>q;
    for(int i = 2; i <= n; ++ i){
        f>>t[i];
        arb[t[i]].push_back(i);
    }

    dfs(1, 1);

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

    for(int i = 1; (1 << i) <= k; ++ i){
        for(int j = 1; j <= k ; ++ j){
            d[i][j] = min(d[i - 1][j], d[i - 1][j + (1 << (i - 1))]);
        }
    }

    for(int i = 2; i <= n; ++ i){
        put[i] = 1 + put[i / 2];
    }

    for(int i = 1; i <= q; ++ i){
        f>>x>>y;
        int xx = poz[x].ff;
        int yy = poz[y].ss;
        if(xx > yy)
            swap(xx, yy);
        l = put[yy - xx + 1];
        if(d[l][xx].ff < d[l][yy - (1 << l) + 1].ff)
            g<<d[l][xx].ss<<'\n';
        else
            g<<d[l][yy - (1 << l) + 1].ss<<'\n';
    }


    return 0;
}