#include <fstream>
#include <vector>
using namespace std;

vector <int>L[100002];
int euler[200002],nvl[200002],a[21][200002],idx[100002],k,n,m;
ifstream fin ("lca.in");
ofstream fout ("lca.out");

void citire()
{
    fin >> n >> m;

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

void dfs(int v, int niv)
{
    euler[++k]=v;
    nvl[k]=niv;
    idx[v]=k;
    for(vector<int>::iterator it=L[v].begin();it!=L[v].end();it++)
        {
            dfs(*it,niv+1);
            euler[++k]=v;
            nvl[k]=niv;
        }
}

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

    int di=(1<<1);
    for(int i=1;di<=k;)
      {
          for(int j=1;j+di-1<=k;j++)
             {if(nvl[a[i-1][j]]<nvl[a[i-1][j+(1<<(i-1))]])
                    a[i][j]=a[i-1][j];
                    else
                    a[i][j]=a[i-1][j+(1<<(i-1))];
             }
          i++;
          di=(1<<i);
      }
}

int lca(int x, int y)
{

    int diff, l, sol, sh;
    int aa = idx[x], bb = idx[y];
    if(aa > bb)
        swap(aa, bb);
    int k=0;
    while((1<<k)<=bb-aa)k++;
    if(k>0)k--;
    if(nvl[a[k][aa]]<nvl[a[k][bb-(1<<k)+1]])
       return euler[a[k][aa]];
       else
       return euler[a[k][bb-(1<<k)+1]];
}

int main()
{
    citire();
    dfs(1,1);
    rmq();
    for(int i=1;i<=m;i++)
        {
            int x, y;
            fin >> x >> y;
            fout << lca(x, y) << "\n";
        }
    return 0;
}