#include <iostream>
#include <fstream>
#include <vector>
#define Nmax 100005

using namespace std;

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

vector <int> v[Nmax];
int n, q, ne;
int rmq[18][2*Nmax], log2[2*Nmax];
int eul[2*Nmax], first[Nmax];
int niv[Nmax];

void dfs(int x, int nv)
{
    niv[x]=nv;
    eul[++ne]=x;
    first[x]=ne;
    for (auto y:v[x])
    {
        dfs(y, nv+1);
        eul[++ne]=x;
    }
}

void build_rmq()
{
    for (int i = 2; i <= ne; i++)
        log2[i]=log2[i/2]+1;

    for (int i = 1; i <= ne; i++)
        rmq[0][i]=eul[i];

    for (int i = 1; (1<<i) <= ne; i++)
        for (int j = 0; j+(1<<i)-1 <= ne; j++)
        {
            int x=rmq[i-1][j];
            int y=rmq[i-1][j+(1<<(i-1))];
            if (niv[x] < niv[y]) rmq[i][j]=x;
            else rmq[i][j]=y;
        }

}

int query(int a, int b)
{
    int x=first[a], y=first[b];
    if (x>y) swap(x, y);

    int i=log2[y-x+1];

    int xx=rmq[i][x];
    int yy=rmq[i][y-(1<<i)+1];

    if (niv[xx] < niv[yy]) return xx;
    else return yy;
}


int main()
{
    f >> n >> q;
    for (int i = 2, t; i <= n; i++)
    {
        f >> t;
        v[t].push_back(i);
    }

    dfs(1, 0);

    build_rmq();
    while (q--)
    {
        int x, y;
        f >> x >> y;
        g << query(x, y) << '\n';
    }

    return 0;
}