#include <bits/stdc++.h>

using namespace std;

const int NMax=100005;
const int LgMax=21;

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

int N,M;
vector<int> G[NMax];
int K,Euler[4*NMax],level[4*NMax],first[2*NMax];
int RMQ[LgMax][4*NMax],lg[4*NMax];

void DFS(int node, int lvl)
{
    Euler[++K]=node;
    first[node]=K;
    level[K]=lvl;
    for(auto child : G[node])
    {
        DFS(child,lvl+1);
        Euler[++K]=node;
        level[K]=lvl;
    }
}

void MakeRMQ()
{
    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(level[RMQ[i][j]]>level[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(level[sol]>level[RMQ[l][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;
        G[x].push_back(i);
    }

    DFS(1,0);
    MakeRMQ();

    for(int i=1;i<=M;i++)
    {
        int x,y;
        fin>>x>>y;
        fout<<LCA(x,y)<<"\n";
    }

    return 0;
}