#include <cstdio>
#include <vector>
#include <cmath>

#define Nmax 100105
#define DIM 2666013
#define next (++pointer == DIM) ? fread(buffer,1,DIM,stdin),pointer = 0 : 0

char buffer[DIM];
int pointer = DIM - 1;

void scanf(int &A){
    A = 0;
    for(;'0'>buffer[pointer]||buffer[pointer]>'9';next);
    for(;'0'<=buffer[pointer]&&buffer[pointer]<='9';next)
        A = A * 10 + buffer[pointer] - 48;
}

using namespace std;
vector<int> G[Nmax];
int N,M;
int euler[18][2*Nmax];
int adanc[18][2*Nmax];
int poz[Nmax],nre;

void read()
{
    scanf(N),scanf(M);
    int a;
    for(int i = 2; i <= N; ++i)
    {
        scanf(a);
        G[a].push_back(i);
    }
}

void DFS(int k,int niv)
{
    euler[0][++nre] = k;
    adanc[0][nre] = niv;
    for(vector<int>::iterator it = G[k].begin(); it != G[k].end(); ++it)
    {
        DFS(*it,niv+1);
        euler[0][++nre] = k;
        adanc[0][nre] = niv;
    }
}

void rmq()
{
    int leng = (int)log2(nre),IT = 1;

    for(int j = 1; j <= leng; ++j)
    {
        for(int i = 1; i <= nre; ++i)
            if(i + IT <= nre)
            {
                if(adanc[j-1][i] < adanc[j-1][i+IT])
                {
                    adanc[j][i] = adanc[j-1][i];
                    euler[j][i] = euler[j-1][i];
                }
                else
                {
                    adanc[j][i] = adanc[j-1][i+IT];
                    euler[j][i] = euler[j-1][i+IT];
                }
            }
            else
            {
                euler[j][i] = euler[j][i-1];
                adanc[j][i] = adanc[j][i-1];
            }

        IT *= 2;
    }
}

void prepare()
{
    DFS(1,0);
    rmq();
}

int Querry(int a,int b)
{
    if(a > b) swap(a,b);
    int lg = min((int)log2(b-a+1),17);
    if(adanc[lg][a] <= adanc[lg][b - (1<<lg) + 1] )
        return euler[lg][a];
    return euler[lg][b - (1<<lg) + 1];
}

void solve()
{
    int a,b;
    for(int i = 1; i <= nre; ++i)
        if(!poz[euler[0][i]])
            poz[euler[0][i]] = i;
    for(int i = 1; i <= M; ++i)
    {
        scanf(a),scanf(b);
        printf("%d\n",Querry(poz[a],poz[b]));
    }
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);

    read();
    prepare();
    solve();

    return 0;
}