#include <fstream>
#include <vector>
#define Nmax 100005
using namespace std;

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

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

void dfs(int x)
{
    eul[++ne]=x;
    first[x]=ne;
    for ( int i = 0, l=ls[x].size(); i < l; i ++ )
    {
        int y=ls[x][i];
        niv[y]=niv[x]+1;
        dfs(y);
        eul[++ne]=x;
    }
}

void range_min()
{
    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 = 1; 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 x, int y)
{
    int a=first[x], b=first[y];
    if(a>b) swap(a,b);

    int diff=b-a+1;
    int i = log2[diff];
    int aa = rmq[i][a];
    int bb = rmq[i][b - (1 << i) + 1];

    if (niv[aa] < niv[bb])
        return aa;
    else return bb;

}

int main()
{
    f >> n >> Q;int tt;
    for ( int i = 1; i < n; i ++ )
     {f >> tt;
      ls[tt].push_back(i+1);
     }
    dfs(1);
    range_min();
    int x, y;
    while(Q--)
    {
        f >> x >> y;
        g << query(x, y) << '\n';
    }

}