#include <bits/stdc++.h>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int pmax=18;
const int nmax=(1<<pmax);
vector<int>L[nmax/2];
int n,rmq[pmax][nmax],query,nod[nmax],niv[nmax],P[nmax/2],pp,p2[nmax];
inline void Read()
{
    fin>>n>>query;
    for(int i=2;i<=n;i++)
    {
        int x;
        fin>>x;
        L[x].push_back(i);
    }
}
void Euler(int varf,int nivel)
{
    ++pp;
    nod[pp]=varf;
    niv[pp]=nivel;
    for(int pas=0;pas<L[varf].size();pas++)
    {
        int i=L[varf][pas];
        Euler(i,nivel+1);
        ++pp;
        nod[pp]=varf;
        niv[pp]=nivel;
    }
    P[varf]=pp;
}
inline void Build()
{
    p2[1]=0;
    for(int i=2;i<=pp;i++)
        p2[i]=1+p2[i/2];
    for(int i=1;i<=pp;i++)
        rmq[0][i]=i;
    for(int i=1;(1<<i)<=pp;i++)
        for(int j=(1<<i);j<=pp;j++)
    {
        int k=(1<<(i-1));
        rmq[i][j]=rmq[i-1][j];
        if(niv[rmq[i][j]]>niv[rmq[i-1][j-k]])
            rmq[i][j]=rmq[i-1][j-k];
    }
}
int main()
{
    Read();
    Euler(1,0);
    Build();
    for(int i=1;i<=query;i++)
    {
        int x,y;
        fin>>x>>y;
        x=P[x];
        y=P[y];
        if(x>y)
            swap(x,y);
        int k=p2[y-x+1],sol=rmq[k][x+(1<<k)-1];
        if(niv[sol]>niv[rmq[k][y]])
            sol=rmq[k][y];
        fout<<nod[sol]<<"\n";
    }
    fin.close();
    fout.close();
    return 0;
}