#include <vector>
#include <fstream>

using namespace std;

#define MAX_N 100005
#define MAX_L 20


int k,n,m;
int L[MAX_N << 1], H[MAX_N << 1],Lg[MAX_N << 1], First[MAX_N];
int Rmq[MAX_L][MAX_N << 2];

vector <int> G[MAX_N];

ifstream f ("lca.in");
ofstream g ("lca.out");

void read()
{
    f >> n >> m;

    for(int i = 2; i <= n; ++i)
    {
        int x;
        f >> x;
        G[x].push_back(i);
    }
}

void df(int nod, int lev)
{
    H[++k] = nod;
    L[k] = lev;
    First[nod] = k;
    vector <int>:: iterator it;
    for(it=G[nod].begin();it!=G[nod].end();++it)
    {
        df(*it, lev+1);

        H[++k] = nod;
        L[k] = lev;
    }
}

void rmq()
{

    for(int i = 2; i <= k; ++i)
        Lg[i] = Lg[i >> 1] + 1;
    for(int i = 1; i <= k; ++i)
        Rmq[0][i] = i;

    for(int i = 1; (1 << i) < k; ++i)
        for(int j = 1; j <= k - (1 << i); ++j)
        {
            int l = 1 << (i - 1);

            Rmq[i][j] = Rmq[i-1][j];
            if(L[Rmq[i-1][j + l]] < L[Rmq[i][j]])
                Rmq[i][j] = Rmq[i-1][j + l];
        }
}

int lca(int x, int y)
{

    int diff, l, sol, sh;
    int a = First[x], b = First[y];
    if(a > b) swap(a, b);
    diff = b - a + 1;
    l = Lg[diff];
    sol = Rmq[l][a];
    sh = diff - (1 << l);
    if(L[sol] > L[Rmq[l][a + sh]])
        sol = Rmq[l][a + sh];
    return H[sol];
}

int main()
{
    read();
    df(1, 0);
    rmq();

    while(m--)
    {
        int x, y;
        f >> x >> y;
        g << lca(x, y) << "\n";
    }
}