#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e5;
const int MAXLOG = 19;

vector < int > g[MAXN + 1];
int lev[MAXN + 1] = {0, 1}, rmq[MAXLOG + 1][2 * MAXN + 2], frst[MAXN + 1], lg[2 * MAXN + 2], aux;

void euler_trav(int node) {
  frst[node] = ++aux;
  rmq[0][aux] = node;
  for (auto it : g[node]) {
    lev[it] = lev[node] + 1;
    euler_trav(it);
    rmq[0][++aux] = node;
  }
}

int main()
{
    int n, m;
    ifstream fin("lca.in");
    fin >> n >> m;
    for (int i = 2; i <= n; ++i) {
      int x;
      fin >> x;
      g[x].push_back(i);
    }
    euler_trav(1);
    for (int i = 1; (1 << i) <= aux; ++i) {
      int p2 = (1 << i);
      for (int j = 1; j <= aux - p2 + 1; ++j)
        if (lev[rmq[i - 1][j]] < lev[rmq[i - 1][j + p2 / 2]])
          rmq[i][j] = rmq[i - 1][j];
        else
          rmq[i][j] = rmq[i - 1][j + p2 / 2];
    }
    for (int i = 2; i <= aux; ++i)
      lg[i] = lg[i / 2] + 1;
    ofstream fout("lca.out");
    for (int i = 0; i < m; ++i) {
      int x, y;
      fin >> x >> y;
      x = frst[x];
      y = frst[y];
      if (x > y)
        swap(x, y);
      int diff = lg[y - x + 1];
      if (lev[rmq[diff][x]] < lev[rmq[diff][y - (1 << diff) + 1]])
        fout << rmq[diff][x] << '\n';
      else
        fout << rmq[diff][y - (1 << diff) + 1] << '\n';
    }
    fin.close();
    fout.close();
    return 0;
}