#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
using namespace std;

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

const int nmax=100001;
int Euler[2*nmax],Level[2*nmax],H[nmax],n,m,k=1,M[2*nmax][19],st,dr,Log[2*nmax];
vector<int> Graf[nmax];

void ST()
{
    k--;
    for(int i=1;i<=k;++i)
        M[i][0]=i;

    for(int j=1; j << 1 <k;++j)
        for(int i=1;i+(1<<j)<=k;++i)
    {
        if(Level[M[i][j-1]]<Level[M[i+(1<<(j-1))][j-1]])
            M[i][j]=M[i][j-1];
        else
            M[i][j]=M[i+(1<<(j-1))][j-1];
    }
}
void parcurgere(int nodCurent,int level)
{
    Level[k]=level;
    Euler[k]=nodCurent;
    if(H[nodCurent]==0)
        H[nodCurent]=k;
    k++;
    for(int i=0;i<Graf[nodCurent].size();++i)
    {
        parcurgere(Graf[nodCurent][i],level+1);
        Level[k]=level;
        Euler[k]=nodCurent;
        k++;
    }

}

int RMQ(int x,int y)
{
    if(x>y)
        swap(x,y);
    int k=Log[y-x+1];
    if(Level[M[x][k]]<Level[M[y-(1<<k)+1][k]])
        return M[x][k];
    else
        return M[y-(1<<k)+1][k];
}

int main()
{

    fin>>n>>m;
    for(int i=2;i<=n;++i)
    {
        fin>>st;
        Graf[st].push_back(i);
    }
    parcurgere(1,0);
    ST();
    for(int i=2;i<=k;++i)
        Log[i]=Log[i/2]+1;
    for(int i=1;i<=m;++i)
    {
        fin>>st>>dr;
        fout<<Euler[RMQ(H[st],H[dr])]<<"\n";
    }

    return 0;
}