#include <iostream>
#include <fstream>
#include <cmath>
#include <vector>
#define N_MAX 100005
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int n, m, P1[N_MAX], P2[N_MAX], L[N_MAX], lg;
vector <int> G[N_MAX];

void build(int nod, int lev)
{
    lg = max(lg, lev);
    for(auto it : G[nod])
        build(it, lev + 1);
}

void dfs(int nod, int p, int lev)
{
    P2[nod] = p;
    L[nod] = lev;
    if(lev % lg == 0) p = nod;
    for(auto it:G[nod])
        dfs(it, p, lev+1);
}

int lca(int x, int y)
{
    while(P2[x] != P2[y])
        if(L[x] < L[y])
            y = P2[y];
        else
            x = P2[x];
    while(x != y)
        if(L[x] < L[y])
            y = P1[y];
        else
            x = P1[x];
    return x;
}
int main()
{
    f >> n >> m;
    for(int i = 2; i <= n; i++)
        f >> P1[i];
    for(int i = 2; i <= n; i++)
        G[P1[i]].push_back(i);
    build(1,0);
    lg = sqrt(lg);
    dfs(1,1,0);
    int nod1, nod2;
    for(int i = 1; i<= m; i++)
    {
        f >> nod1 >> nod2;
        g << lca(nod1, nod2) << "\n";
    }
    return 0;
}