#include <iostream>
#include <fstream>
#include <vector>
#include <math.h>
using namespace std;
int n,m,A[200005],M[200005][26],top,poz[100005];
vector <int> L[100002];
bool v[100005];

void RMQ()
{
    int i,j=1,p;

    for(j=1,p=2;p<top;j++,p*=2)
    {
        for(i=0;i+p-1<top;i++)
        {
            M[i][j]=min(M[i][j-1],M[i+p/2][j-1]);
        }
    }

}

void dfs(int nod)
{
    v[nod]=true;
    M[top++][0]=nod;
    poz[nod]=top-1;
    for(unsigned int i=0;i<L[nod].size();i++)
    {
        if(v[L[nod][i]]==false)
        {
            dfs(L[nod][i]);
            M[top++][0]=nod;
        }
    }
}


void Afisare()
{
    for(int i=0;i<top;i++)
    {
        for(int j=0;j<sqrt(top)+1;j++)
            cout<<M[i][j]<<" ";
        cout<<"\n";
    }
}

int main()
{
    int i,x,y,aux,k;

    ifstream fin("rmq.in");
    ofstream fout("rmq.out");
    fin>>n>>m;
    for(i=2;i<=n;i++)
    {
        fin>>x;
        L[i].push_back(x);
        L[x].push_back(i);
    }
    dfs(1);
    RMQ();
    //Afisare();
    //cout<<top;
    for(i=0;i<m;i++)
    {
        fin>>x>>y;
        if(x>y) swap(x,y);
        aux=1;
        k=0;
        while(aux<=poz[y]-poz[x]+1)
        {
            k++;
            aux*=2;
        }
        k--;
        aux/=2;
        //cout<<aux<<"\n";
        fout<<min(M[poz[x]][k],M[poz[y]-aux+1][k])<<"\n";
    }
    //cout<<"\n\n"<<poz[2]<<" "<<poz[4];
    fin.close();
    fout.close();
    return 0;
}