#include <bits/stdc++.h>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const short Pmax=18;
const  int Nmax=(1<<18);
vector<int>L[Nmax/2];
int AP[Nmax/2],nod[Nmax],nivel[Nmax],RMQ[Pmax][Nmax],put2[Nmax],n,m,Q;
inline void READ()
{
    fin>>n>>Q;
    for(int i=2;i<=n;i++)
    {
        int x;
        fin>>x; ///x->tatal nodului i
        L[x].push_back(i);
    }
}
void EULER(int varf,int niv)
{
    ++m;
    nod[m]=varf;
    nivel[m]=niv;
    for(auto i:L[varf])
    {
        EULER(i,niv+1);
        ++m;
        nod[m]=varf;
        nivel[m]=niv;
    }
    AP[varf]=m; ///ultima aparitie a varfului "varf" in parcurgerea Euler
}
inline void BUILD()
{
    int k,x,y;
    put2[1]=0;
    for(int i=2;i<=m;i++)
        put2[i]=put2[i/2]+1;
    ///in RMQ retin pozitiile minimului
    for(int i=1;i<=m;i++)
        RMQ[0][i]=i;
    for(int i=1;(1<<i)<=m;i++)
        for(int j=(1<<i);j<=m;j++)
    {
        k=(1<<(i-1));
        RMQ[i][j]=RMQ[i-1][j];
        x=nivel[RMQ[i-1][j]];
        y=nivel[RMQ[i-1][j-k]];
        if(x>y)
            RMQ[i][j]=RMQ[i-1][j-k];
    }
}
int main()
{
    int x,y,c,c1,lug,k,sol;
    READ();
    EULER(1,0);
    BUILD();
    while(Q--)
    {
        fin>>c>>c1;
        x=min(AP[c],AP[c1]);
        y=max(AP[c],AP[c1]);
        lug=(y-x+1);
        k=put2[lug];
        sol=RMQ[k][y];
        if(sol>nivel[RMQ[k][x+(1<<k)-1]])
            sol=RMQ[k][x+(1<<k)-1];
        fout<<nod[sol]<<"\n";
    }
    fin.close();
    fout.close();
    return 0;
}