#include<bits/stdc++.h>
using namespace std;
FILE *f=fopen("lca.in","r");
FILE *g=fopen("lca.out","w");
const int NMAX = 100001;
vector<int>G[NMAX];
int N,M;

struct{int nod,nivel;}v[4*NMAX];
int vCount=0;
int first[NMAX]; /// first[i] este prima aparitie a nodului i in vectorul v
bitset<NMAX>viz;
void Read()
{
    fscanf(f,"%d%d",&N,&M);
    for(int i=1;i<N;i++)
    {
        int x;fscanf(f,"%d",&x);
        /// adaugam muchie de la tata la fiu
        G[x].push_back(i+1);
    }
}
void Dfs(int nodCurent,int nivel)
{
    viz[nodCurent]=true;

    /// adaugam nodul la inceput
    v[++vCount].nod = nodCurent;
    v[vCount].nivel = nivel;

    if(first[nodCurent]==0) first[nodCurent]=vCount;

    for(auto nodVecin : G[nodCurent])
    {
        if(viz[nodVecin])continue;
        Dfs(nodVecin,nivel+1);
        /// adaugam nodul dupa fiecare fiu
        v[++vCount].nod = nodCurent;
        v[vCount].nivel = nivel;
    }

}
int LCA(int x,int y)
{
    int nivelMinim = INT_MAX;
    int stramos = -1;
    int i = first[x];
    while(nivelMinim>0)
    {
        if(v[i].nivel<nivelMinim)nivelMinim=v[i].nivel,stramos= v[i].nod;
        if(v[i].nod==y)break;
        i++;
    }
    return stramos;
}
void Solve()
{
    Dfs(1,0);
    int x,y;
    for(int m=1;m<=M;m++)
    {
        fscanf(f,"%d%d",&x,&y);
        fprintf(g,"%d\n",LCA(x,y));
    }
}
int main()
{
    Read();
    Solve();
    fclose(f);
    fclose(g);
    return 0;
}