#include <bits/stdc++.h>

#define NMax 100005
#define H 200

using namespace std;

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

int N,M,K;
vector<int> Graf[NMax];
int Euler[4*NMax],First[4*NMax],niv[4*NMax],lg[4*NMax];
int RMQ[18][4*NMax];

void DFS(int nod,int nivel)
{
    Euler[++K]=nod;
    niv[K]=nivel;
    First[nod]=K;
    for(vector<int>::iterator it=Graf[nod].begin();it!=Graf[nod].end();it++)
    {
        DFS(*it,nivel+1);
        Euler[++K]=nod;
        niv[K]=nivel;
    }
}

void rmq()
{
    for(int i=2;i<=K;i++)
        lg[i]=lg[i/2]+1;
    for(int i=1;i<=K;i++)
        RMQ[0][i]=i;
    for(int i=1;(1<<i)<=K;i++)
        for(int j=1;j<=K-(1<<i);j++)
        {
            int l=1<<(i-1);
            RMQ[i][j]=RMQ[i-1][j];
            if(niv[RMQ[i][j]]>niv[RMQ[i-1][j+l]])
                RMQ[i][j]=RMQ[i-1][j+l];
        }
}

int LCA(int x,int y)
{
    x=First[x];
    y=First[y];
    if(x>y)
        swap(x,y);
    int l=lg[y-x+1];
    int sol=RMQ[l][x];
    if(niv[sol]>niv[RMQ[1][y-(1<<l)+1]])
        sol=RMQ[l][y-(1<<l)+1];
    return Euler[sol];
}

int main()
{
    fin>>N>>M;
    for(int i=2;i<=N;i++)
    {
        int x;
        fin>>x;
        Graf[x].push_back(i);
    }
    DFS(1,0);
    rmq();
    while(M--)
    {
        int x,y;
        fin>>x>>y;
        fout<<LCA(x,y)<<"\n";
    }

    return 0;
}