# include <fstream>
# include <algorithm>
# include <vector>
# define NR 100005
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
vector <int> v[NR];
struct elem
{
    int niv, k;
}a[20][NR], st[NR];

int i,j,n,m,k,L,VV,Q,x,y;
int poz[NR], lg[NR];

void DFS (int k, int nivel)
{
    st[++VV].k=k; st[VV].niv=nivel;
    poz[k]=VV;
    for (int i=0; i<v[k].size(); ++i)
        if (! poz[v[k][i]])
        {
            DFS (v[k][i], nivel+1);
            st[++VV].k=k; st[VV].niv=nivel;
        }
}
int main ()
{
    f>>n>>Q;
    for (i=2; i<=n; ++i)
    {
        f>>x;
        v[x].push_back(i);
    }

    DFS (1, 0);

    for (i=2; i<=VV; ++i)
        lg[i]=lg[i/2]+1;

    for (i=1; i<=VV; ++i)
        a[0][i]=st[i];
    for (i=1; i<=lg[VV]; ++i)
        for (j=1; j<=VV-(1<<(i-1))+1; ++j)
        {
            if (a[i-1][j].niv < a[i-1][j+(1<<(i-1))].niv) a[i][j]=a[i-1][j];
                                                  else  a[i][j]=a[i-1][j+(1<<(i-1))];
        }

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

        int L=lg[CS-CI+1];

        if (a[L][CI].niv < a[L][CS-(1<<L)+1].niv) g<<a[L][CI].k<<"\n";
                                            else  g<<a[L][CS-(1<<L)+1].k<<"\n";
    }


    return 0;
}