#include <bits/stdc++.h>

using namespace std;

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

int n, q, m, x, y;

int depth[300005], p[300005], v[300005], log1[300005];
int rmq[200005][20];
vector <int> g[300005];

void dfs(int nod, int cnt) {
  depth[nod] = cnt;
  v[++m] = nod;
  for(auto i : g[nod]) {
    dfs(i, cnt + 1);
    v[++m] = nod;
  }
}

int findmin(int l, int r) {
  int d = r - l + 1, lg = log1[d];
  if(depth[rmq[l][lg]] > depth[rmq[r - (1 << lg) + 1][lg]])
    return rmq[r - (1 << lg) + 1][lg];
  return rmq[l][lg];
}

int main() {
  in >> n >> q;
  for(int i = 1; i < n; i++) {
    in >> x;
    g[x].push_back(i + 1);
  }
  dfs(1, 1);
  for(int i = 1; i <= m; i++) {
    if(!p[v[i]])
      p[v[i]] = i;
  }
  rmq[1][0] = v[1];
  for(int i = 2; i <= m; i++) {
    log1[i] = log1[i / 2] + 1;
    rmq[i][0] = v[i];
  }
  for(int j = 1; (1 << j) <= m; j++) {
    for(int i = 1; i <= m - (1 << j) + 1; i++) {
      rmq[i][j] = rmq[i + (1 << (j - 1))][j - 1];
      if(depth[rmq[i + (1 << (j - 1))][j - 1]] > depth[rmq[i][j - 1]])
        rmq[i][j] = rmq[i][j - 1];
    }
  }
  for(; q; q--) {
    in >> x >> y;
    x = p[x]; y = p[y];
    if(x > y)
      swap(x, y);
    out << findmin(x, y) << "\n";
  }
  return 0;
}