#include <bits/stdc++.h>
#define Nmax 100005
using namespace std;

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

int N, M, K;
vector <int> G[Nmax];
int E[2 * Nmax], lg[2 * Nmax], lev[2 * Nmax], rmq[2 * Nmax][20], pos[Nmax];

void update(int node, int father) {
    E[++K] = node;
    lev[K] = lev[pos[father]] + 1;
    if (!pos[node]) pos[node] = K;
}
void DFS(int node, int father) {
    update(node, father);
    for (auto it: G[node]) {
        DFS(it, node);
        update(node, father);
    }
}
void RMQ() {
   for (int i = 2; i <= K; ++i)
      lg[i] = lg[i / 2] + 1;
   for (int i = 1; i <= K; ++i)
      rmq[i][0] = i;

   for (int j = 1; (1 << j) <= K; ++j)
   for (int i = 1; i + (1 << j) - 1 <= K; ++i) {
      int a = rmq[i][j - 1], b = rmq[i + (1 << (j - 1))][j - 1];
      if (lev[a] < lev[b]) rmq[i][j] = a;
      else rmq[i][j] = b;
   }
}
int compute(int x, int y) {
   int mid = lg[y - x + 1];
   int a = rmq[x][mid], b = rmq[y - (1 << mid) + 1][mid];
   if (lev[a] < lev[b]) return E[a];
   return E[b];
}
int main()
{
    f >> N >> M;
    for (int i = 2; i <= N; ++i) {
        int x;
        f >> x;
        G[x].push_back(i);
    }
    DFS(1, 0), RMQ();

    for (int i = 1; i <= M; ++i) {
        int x, y;
        f >> x >> y;
        if (pos[x] > pos[y]) swap(x, y);
        g << compute(pos[x], pos[y]) << '\n';
    }

    return 0;
}