#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

typedef pair<int,int> ipair;

const int nmax = 1e5 + 1;
const int lmax = 20;

static int n, m;

vector<int> adj[nmax];
vector<int> path;

static int ap[nmax];
static int par[nmax];
static int level[nmax * 2];
static int rmq[lmax][nmax * 2];

int count = 0;

void __lin(int u) {
  if (!ap[u]) ap[u] = count;
  rmq[0][count++] = u;
  for (int &v : adj[u]) {
    level[v] = level[u] + 1;
    __lin(v);
    rmq[0][count++] = u;
  }
}

void __rmq() {
  for (int i = 1; (1 << i) <= count; i++) {
    for (int j = 0; j + (1 << i) <= count; j++) {
      int a = rmq[i - 1][j], b = rmq[i - 1][j + (1 << (i - 1))];
      rmq[i][j] = level[a] < level[b] ? a : b;
    }
  }
}

int32_t main() {
  freopen("lca.in", "r", stdin);
  freopen("lca.out", "w", stdout);

  cin >> n >> m;
  for (int i = 2; i <= n; i++) {
    cin >> par[i];
    adj[par[i]].push_back(i);
  }

  level[1] = 1;
  __lin(1);
  __rmq();

  int a, b, d, x, y, r;
  for (int i = 1; i <= m; i++) {
    cin >> a >> b;
    a = ap[a], b = ap[b];
    if (a > b) swap(a, b);
    d = (int)log2(b - a + 1);
    x = rmq[d][a], y = rmq[d][b - (1 << d) + 1];
    r = level[x] < level[y] ? x : y;
    cout << r << endl;
  }

}