#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#define MAXN 100000
#define MAXL 20
using namespace std;

int first[MAXN + 5];
int euler[(MAXN << 1) + 5];
int lv[(MAXN << 1) + 5];
int lg[(MAXN << 1) + 5];
int RMQ[MAXL][(MAXN << 2) + 5];
vector<int> son[MAXN + 5];
int N, M, pos, x, y;

void build(int node, int level) {
   euler[++pos] = node;
   lv[pos] = level;
   first[node] = pos;
   for(int i = 0; i < son[node].size(); ++i) {
      build(son[node][i], level + 1);
      euler[++pos] = node;
      lv[pos] = level;
   }
}

void rmq() {
   for(int i = 2; i <= pos; ++i) {
      lg[i] = lg[i / 2] + 1;
   }
   for(int i = 1; i <= pos; ++i) {
      RMQ[0][i] = i;
   }
   for(int i = 1; (1 << i) < pos; ++i) {
      for(int j = 1; j <= pos - (1 << i); ++j) {
         int l = 1 << (i - 1);
         RMQ[i][j] = RMQ[i - 1][j];
         if(lv[RMQ[i - 1][j + l]] < lv[RMQ[i][j]])
            RMQ[i][j] = RMQ[i - 1][j + l];
      }
   }
}

int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    cin >> N >> M;
    for(int i = 2; i <= N; ++i) {
      cin >> x;
      son[x].push_back(i);
    }
    build(1, 0);
    rmq();
    for(int i = 1; i <= M; ++i) {
      cin >> x >> y;
      int a = first[x], b = first[y];
      if(a > b)
         swap(a, b);
      int dif = b - a + 1;
      int l = lg[dif];
      int ans = RMQ[l][a];
      if(lv[ans] > lv[RMQ[l][a + dif - (1 << l)]])
        ans = RMQ[l][a + dif - (1 << l)];
    cout << euler[ans] << '\n';
    }
    return 0;
}