#include <fstream>
#include <vector>

#define NMax 100005
#define EMax 500005
#define LgMax 30

using namespace std;

vector <int> G[NMax];
int N, Level[EMax], NEuler, Euler[EMax], First[NMax];
int RMQ[LgMax][EMax], Log2[EMax];

void DFS (int X, int L)
{
    ++NEuler;
    Level[NEuler]=L;
    Euler[NEuler]=X;
    if (First[X]==0)
    {
        First[X]=NEuler;
    }
    for (unsigned v=0; v<G[X].size (); ++v)
    {
        int V=G[X][v];
        DFS (V, L+1);
        ++NEuler;
        Level[NEuler]=L;
        Euler[NEuler]=X;
    }
}

inline int MinRMQ (int a, int b)
{
    if (Level[a]<Level[b])
    {
        return a;
    }
    return b;
}

void Initialize ()
{
    for (int i=1; i<=NEuler; ++i)
    {
        RMQ[0][i]=i;
        if (i>1)
        {
            Log2[i]=Log2[i/2]+1;
        }
    }
}

void BuildRMQ ()
{
    Initialize ();
    for (int l=1; l<=Log2[NEuler]; ++l)
    {
        int n=NEuler-(1<<l)+1;
        for (int i=1; i<=n; ++i)
        {
            RMQ[l][i]=MinRMQ (RMQ[l-1][i], RMQ[l-1][i+(1<<(l-1))]);
        }
    }
}

inline int Query (int A, int B)
{
    int L=B-A+1, Dif=L-(1<<Log2[L]);
    return MinRMQ (RMQ[Log2[L]][A], RMQ[Log2[L]][A+Dif]);
}

int main()
{
    ifstream fin ("lca.in");
    ofstream fout ("lca.out");
    int N, Q;
    fin >> N >> Q;
    for (int i=2; i<=N; ++i)
    {
        int X;
        fin >> X;
        G[X].push_back (i);
    }
    DFS (1, 1);
    BuildRMQ ();
    for (; Q>0; --Q)
    {
        int QX, QY;
        fin >> QX >> QY;
        if (First[QX]>First[QY])
        {
            int Aux=QX;
            QX=QY;
            QY=Aux;
        }
        fout << Euler[Query (First[QX], First[QY])] << "\n";
    }
    return 0;
}