#include <iostream>
#include <cstdio>
#include <vector>
#define NMAX 100000

using namespace std;

int ord, n, m;
int log[2 * NMAX + 5], euler[2 * NMAX + 5], level[NMAX + 5], f[NMAX + 5];
int rmq[20][2 * NMAX + 5];
vector<int> v[NMAX + 5];

void gen_log() {
  log[1] = 0;
  for(int i = 2; i <= 2 * n - 1; i++)
    log[i] = log[i / 2] + 1;
}

void dfs(int x) {
  euler[ord++] = x;
  if(!f[x])
    f[x] = ord - 1;
  for(int y: v[x]) {
    level[y] = level[x] + 1;
    dfs(y);
    euler[ord++] = x;
  }
}

int minim(int a, int b) {
  if(level[a] != level[b])
    return (level[a] < level[b]) ? a : b;
  return (a < b) ? a : b;
}

void gen_rmq() {
  for(int i = 0; i <= log[2 * n - 1]; i++)
    for(int j = 1; j + (1 << i) - 1 <= 2 * n - 1; j++)
      if(i == 0)
        rmq[0][j] = euler[j];
      else
        rmq[i][j] = minim(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);
}

int get_lca(int fx, int fy) {
  if(fx > fy)
    swap(fx, fy);
  int l = log[fy - fx + 1];

  return minim(rmq[l][fx], rmq[l][fy - (1 << l) + 1]);
}

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

  scanf("%d %d", &n, &m);
  gen_log();
  for(int i = 2; i <= n; i++) {
    scanf("%d", &x);
    v[x].push_back(i);
  }

  ord = 1;
  level[1] = 0;
  dfs(1);

  gen_rmq();

  for(int i = 1; i <= m; i++) {
    scanf("%d %d", &x, &y);
    printf("%d\n", get_lca(f[x], f[y]));
  }

  return 0;
}