#include <bits/stdc++.h>

using namespace std;

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

vector<int>graph[100005];

int n, nr_q,x, euler[200005], inaltime=0, valput, a, b;
int sp[200005][20], ind_euler=1, first[100005], height[200005];

void create_euler(int ind)
{
    if (!first[ind])
        first[ind]=ind_euler;
    euler[ind_euler]=ind;
    height[ind_euler++]=inaltime;
    for (auto &v:graph[ind])
    {
        inaltime++;
        create_euler(v);
        inaltime--;
        euler[ind_euler]=ind;
        height[ind_euler++]=inaltime;
    }

}

void create_sp()
{
    for (int i=1; i<ind_euler; ++i)
        sp[i][0]=i;
    for (int putere=1; (1<<putere)<=ind_euler; ++putere)
    {
        valput=(1<<putere);
        for (int i=1; i+valput<ind_euler; ++i)
        {
            if (height[sp[i][putere-1]]<height[sp[i+(valput>>1)][putere-1]])
                sp[i][putere]=sp[i][putere-1];
            else
                sp[i][putere]=sp[i+(valput>>1)][putere-1];
        }
    }
}

int query(int st, int dr)
{
    if (st>dr)
        swap(st,dr);
    int dif=dr-st+1;
    int vallog=log2(dif);
    int vst=sp[st][vallog];
    int vdr=sp[dr-(1<<vallog)+1][vallog];
    if (height[vst]<height[vdr])
        return euler[vst];
    return euler[vdr];
}

int main()
{
    f >> n >> nr_q;
    for (int i=2; i<=n; ++i)
    {
        f >> x;
        graph[x].push_back(i);
    }
    create_euler(1);
    create_sp();
    for(int i=1; i<=nr_q; ++i)
    {
        f >> a >> b;
        g << query(first[a],first[b])  << '\n';
    }
    return 0;
}