#include <iostream>
#include <fstream>
#include <vector>
#define lim 100001
using namespace std;

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

int n, m, E[lim<<1], Lev[lim<<1], Lg[lim<<1], First[lim<<1], t = 0, rmq[lim<<2][20];
vector<int> G[lim];

void Dfs(int node, int lev)
{
    E[++t] = node;
    Lev[t] = lev;
    First[node] = t;
    for(vector<int> :: iterator it = G[node].begin(); it != G[node].end(); ++it)
    {
        Dfs(*it, lev+1);
        E[++t] = node;
        Lev[t] = lev;
    }
}

void Rmq()
{
    for(int i = 2; i <= t; ++i)
        Lg[i] = Lg[i>>1] + 1;
    for(int i = 1; i <= t; ++i)
        rmq[i][0] = i;
    for(int j = 1; (1<<j) < t; ++j)
        for(int i = 1; i+(1<<j)-1 <= t; ++i)
        if(Lev[rmq[i][j-1]] > Lev[rmq[i+(1<<(j-1))][j-1]])
            rmq[i][j] = rmq[i+(1<<(j-1))][j-1];
        else
            rmq[i][j] = rmq[i][j-1];
}

int main()
{
    f >> n >> m;
    for(int i = 2; i <= n; ++i)
    {
        int x;
        f >> x;
        G[x].push_back(i);
    }
    Dfs(1, 0);
    Rmq();
    for(int i = 1; i <= m; ++i)
    {
        int x, y, sol, f1, f2, md, rq;
        f >> x >> y;
        f1 = First[x], f2 = First[y];
        if(f1 > f2) swap(f1, f2);
        md = f2 -f1 +1;
        rq = 1<<Lg[md];
        if(Lev[rmq[f1][Lg[md]]] > Lev[rmq[f2-rq+1][Lg[md]]])
            sol = rmq[f2-rq+1][Lg[md]];
        else sol = rmq[f1][Lg[md]];
        g << E[sol] << "\n";
    }
}