#include <bits/stdc++.h>

using namespace std;

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

int N , Q , K , niv[210000] , euler[210000] , dp[21][210000] , poz[100001];
vector <int> adList[100001];
int p[210000];

void DFS (int V , int P)
{
    niv[V] = niv[P] + 1;
    euler[++K] = V;
    poz[V] = K;
    for (int U : adList[V])
    {
        if(U != P)
            DFS(U , V);
        euler[++K] = U;
    }
}

void Calc ()
{
    p[1] = 0;
    for(int i = 2; i <= K; ++i)
        p[i] = 1 + p[i / 2];
    for(int i = 1; i <= K; ++i)
        dp[0][i] = euler[i];
    for(int i = 1; (1 << i) <= K; ++i)
        for(int j = 1; j <= K; ++j)
        {
            dp[i][j] = dp[i - 1][j];
            int p = (1 << (i - 1));
            if(niv[dp[i - 1][j - p]] < niv[dp[i - 1][j]])
                dp[i][j] = dp[i - 1][j - p];
        }
}

int LCA (int A , int B)
{
    int st = poz[A] , dr = poz[B];
    if(st > dr)
        swap(st , dr);
    int l = p[dr - st + 1];
    int p = (1 << l);
    A = dp[l][st + p - 1];
    B = dp[l][dr];
    if(niv[A] < niv[B])
        return A;
    return B;
}

int main()
{
    fin >> N >> Q;
    for(int i = 2; i <= N; ++i)
    {
        int X;
        fin >> X;
        adList[i].push_back(X);
        adList[X].push_back(i);
    }
    DFS (1 , 0);
    Calc();
    while (Q --)
    {
        int A , B;
        fin >> A >> B;
        fout << LCA(A , B) << "\n";
    }
}