#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pli pair<ll,int>
#define pil pair<int,ll>
#define fi first
#define se second
#define inf (INT_MAX/2-1)
#define infl (1LL<<60)
#define vi vector<int>
#define vl vector<ll>
#define pb push_back
#define sz(a) (int)(a).size()
#define all(a) begin(a),end(a)
#define y0 y5656
#define y1 y7878
#define aaa system("pause");
#define dbg(x) cerr<<(#x)<<": "<<(x)<<'\n',aaa
#define dbga(x,n) cerr<<(#x)<<"[]: ";for(int _=0;_<n;_++)cerr<<x[_]<<' ';cerr<<'\n',aaa
#define dbgs(x) cerr<<(#x)<<"[stl]: ";for(int _:x)cerr<<_<<' ';cerr<<'\n',aaa
#define dbgp(x) cerr<<(#x)<<": "<<x.fi<<' '<<x.se<<'\n',aaa
#define maxn 100000

using namespace std;

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

vi fii[maxn+5];
int tata[maxn+5];

struct LCA {
  LCA () {}
  vi tour;
  int niv[maxn+5], fapr[maxn+5], rmq[2*maxn+5][18+5], lg[2*maxn+5];
  void dfst (int nod) {
    niv[nod] = 1+niv[tata[nod]];
    for (int nn: fii[nod]) dfst(nn);
  }
  void dfs (int nod) {
    if (fapr[nod] == -1) fapr[nod] = sz(tour);
    tour.pb(nod);
    for (int nn: fii[nod]) {
      dfs(nn);
      tour.pb(nod);
    }
  }
  int query (int a, int b) {
    a = fapr[a]; b = fapr[b];
    if (a > b) swap(a, b);
    int ile = lg[b-a+1];
    int ans = rmq[b-(1<<ile)+1][ile];
    if (niv[ans] > niv[rmq[a][ile]]) ans = rmq[a][ile];
    return ans;
  }
  void prelca () {
    int i, j, z;
    dfst(1);
    fill(all(fapr), -1);
    dfs(1);
    int m = sz(tour);
    for (i = 2; i <= m; i++) lg[i] = lg[i>>1] + 1;
    for (i = 0; i < m; i++) rmq[i][0] = tour[i];
    for (j = 1; j <= lg[m]; j++)
      for (i = 0; i+(1<<j)-1 < m; i++) {
        rmq[i][j] = rmq[i+(1<<(j-1))][j-1];
        if (niv[rmq[i][j]] > niv[rmq[i][j-1]]) rmq[i][j] = rmq[i][j-1];
      }
  }
};

LCA lca;

int main () {
  int n, m; fin >> n >> m;
  int i, j, z;
  for (i = 2; i <= n; i++) {
    fin >> tata[i];
    fii[tata[i]].pb(i);
  }
  lca.prelca();
  while (m--) {
    int a, b; fin >> a >> b;
    fout << lca.query(a, b) << '\n';
  }
  fin.close(); fout.close();
  return 0;
}