#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n, q, pstart[20005], p, e[200005];
vector <int> l[100001];

struct elemrmq
{
    int nod, niv;
}rmq[20][200005];

void dfs(int nod, int niv=1)
{
    rmq[0][++p]={nod, niv};
    pstart[nod]=p;
    for(int i=0; i<l[nod].size(); i++)
    {
        int vecin=l[nod][i];
        dfs(vecin, niv+1);
        rmq[0][++p]={nod, niv};
    }
}

void calcul_rmq()
{
    for(int putere=1; putere<20; putere++)
    {
        for(int i=1; i<=p; i++)
        {
            elemrmq st=rmq[putere-1][i];
            if(i+(1<<(putere-1)) <= p)
            {
                elemrmq dr=rmq[putere-1][i+(1<<(putere-1))];
                rmq[putere][i]=st.niv<dr.niv ? st : dr;
            }
            else
            {
                rmq[putere][i]=st;
            }
        }
    }
}

void puteri()
{
    e[1]=0;
    for(int i=2; i<=p; i++)
        e[i]=e[i/2]+1;
}

int lca(int x, int y)
{
    int pozx=pstart[x];
    int pozy=pstart[y];
    if(pozx > pozy)
    {
        swap(pozx, pozy);
    }
    int putere=e[pozy-pozx+1];
    elemrmq st=rmq[putere][pozx];
    elemrmq dr=rmq[putere][pozy-(1<<putere)+1];
    if(st.niv<dr.niv)
        return st.nod;
    else
        return dr.nod;
}

int main()
{
    fin>>n>>q;
    for(int i=2; i<=n; i++)
    {
        int parinte;
        fin>>parinte;
        l[parinte].push_back(i);
    }
    p=0;
    dfs(1);
    calcul_rmq();
    puteri();
    while(q--)
    {
        int x, y;
        fin>>x>>y;
        fout<<lca(x, y)<<"\n";
    }
    return 0;
}