#include <iostream>
#include <fstream>
#include <vector>

#define NMAX 100005

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

int n, m, L, rmq[20][2*NMAX], log[2*NMAX];
int euler[2*NMAX], niv[NMAX], first[NMAX];
vector <int> v[NMAX];

void citire()
{
    fin>>n>>m;
    int x;
    for(int i=2;i<=n;i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
}

void formare_euler(int nod, int nivel)
{
    euler[++L]=nod;
    niv[L]=nivel;
    first[nod]=L;
    for(unsigned int i=0;i<v[nod].size();i++)
    {
        formare_euler(v[nod][i],nivel+1);
        euler[++L]=nod;
        niv[L]=nivel;
    }
}

void range()
{
    for(int i = 1; i <= L; ++i)
		rmq[0][i] = i;

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

			rmq[i][j] = rmq[i-1][j];
			if(niv[rmq[i-1][j + l]] < niv[rmq[i][j]])
				rmq[i][j] = rmq[i-1][j + l];
		}
}

int lca(int x, int y)
{
    int a=first[x], b=first[y];
    if(a>b)
        swap(a,b);
    int dif, l1, l2, sol1, sol2;
    dif=b-a+1;
    l1=log[dif];
    sol1=rmq[l1][a];
    l2=dif-(1<<l1);
    sol2=rmq[l1][a+l2];
    if(niv[sol1]>niv[sol2])
        sol1=sol2;
    return euler[sol1];
}

int main()
{
    citire();
    formare_euler(1,1);
    range();
    int x, y;
    log[1]=0;
    for(int i=2;i<=L;i++)
        log[i]=log[i/2]+1;
    while(m)
    {
        m--;
        fin>>x>>y;
        fout<<lca(x,y)<<'\n';
    }
    return 0;
}