# include <fstream>
# include <vector>
# include <algorithm>
# define NR 100005
# define inf 999999999
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
vector <int> v[NR];
struct elem
{
    int k, niv;
}st[2*NR], ARB[4*NR];

int i,j,n,m,x,y,Q,VV,I,CI,CS,minn,POZ,S;
int poz[NR];

void DFS (int k, int niv)
{
    st[++VV].k=k; st[VV].niv=niv;
    poz[k]=VV;

    for (int i=0; i<v[k].size(); ++i)
    {
        DFS (v[k][i], niv+1);
        st[++VV].k=k; st[VV].niv=niv;
    }

}
void update (int nod, int ci, int cs)
{
    if (ci==cs) ARB[nod]=st[I];
    else {
             int mij=(ci+cs)/2;
             if (I<=mij) update (2*nod, ci, mij);
             if (I>mij) update (2*nod+1, mij+1, cs);

             if (ARB[2*nod].niv < ARB[2*nod+1].niv) ARB[nod]=ARB[2*nod];
                                              else  ARB[nod]=ARB[2*nod+1];
         }
}
void cauta (int nod, int ci, int cs)
{
    if (CI<=ci && cs<=CS)
    {
        if (ARB[nod].niv < minn) minn=ARB[nod].niv, POZ=ARB[nod].k;
    }
    else {
              int mij=(ci+cs)/2;
              if (CI<=mij) cauta (2*nod, ci, mij);
              if (CS>mij) cauta (2*nod+1, mij+1, cs);
         }
}
int main ()
{
    f>>n>>Q;
    for (i=2; i<=n; ++i)
    {
        f>>x;
        v[x].push_back(i);
    }
    DFS(1, 0);

    for (i=1; i<=VV; ++i)
    {
        I=i;
        update (1, 1, VV);
    }

    for (i=1; i<=Q; ++i)
    {
        f>>x>>y;
        CI=min(poz[x], poz[y]); CS=max(poz[x], poz[y]);

        minn=inf;
        cauta (1, 1, VV);
        g<<POZ<<"\n";
    }



    return 0;
}