#include <fstream>
#include <vector>

using namespace std;

ifstream cin("lca.in");
ofstream cout("lca.out");

int tata[100005],poz=1,n;

vector<int>fii[100005];

pair<int,int>pu[100005];

int grad[100005];

int v[300005];

int rmq[20][300005];

int lg2[300005];

void euler(int nod)
{
    pu[nod].first=poz;
    v[poz]=nod;
    for(int i=0;i<fii[nod].size();i++)
    {
        poz++;
        grad[fii[nod][i]]=grad[nod]+1;
        euler(fii[nod][i]);
        v[poz]=nod;
    }
    pu[nod].second=poz;
    poz++;
}

void build()
{
    for(int i=1;i<=poz;i++)
        rmq[0][i]=v[i];
    for(int i=1;i<=lg2[poz];i++)
    {
        for(int j=1;j<=poz-(1<<i)+1;j++)
        {
            if(grad[rmq[i-1][j]]<=grad[rmq[i-1][j+(1<<(i-1))]])
                rmq[i][j]=rmq[i-1][j];
            else
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
        }
    }
}

int fct(int a,int b)
{
    int dif=b-a+1;
    if(grad[rmq[lg2[dif]][a]]<=grad[rmq[lg2[dif]][b-(1<<lg2[dif])+1]])
        return rmq[lg2[dif]][a];
    return rmq[lg2[dif]][b-(1<<lg2[dif])+1];
}

int query(int a,int b)
{
    if(pu[a].first>pu[b].first)
        swap(a,b);
    if(pu[a].second>pu[b].second)
        return a;
    else
        return fct(pu[a].second,pu[b].first);
}

int main()
{
    for(int i=2;i<300000;i++)
        lg2[i]=lg2[i/2]+1;
    int m;
    cin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        cin>>tata[i];
        fii[tata[i]].push_back(i);
    }
    euler(1);
    build();
    for(int i=0;i<m;i++)
    {
        int a,b;
        cin>>a>>b;
        cout<<query(a,b)<<'\n';
    }
    return 0;
}