#include<bits/stdc++.h>
#define in f
#define out g
using namespace std;

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

int const MAXSIZE = 100010;

int n, m, x, a, b, k;
int dad[MAXSIZE];
int father[MAXSIZE];
vector<int> graph[MAXSIZE];
int depth[MAXSIZE];

int dfs (int node, int f) {
    father[node] = f;
    if (depth[node] % k == 0)
        f = node;
    for (int i = 0; i < graph[node].size(); i++) {
        int adj = graph[node][i];
        depth[adj] = depth[node] + 1;
        dfs(adj, f);
    }
}

int main() {
    in >> n >> m;
    k = sqrt(n);
    for (int i = 2; i <= n; i++) {
        in >> x;
        dad[i] = x;
        graph[x].push_back(i);
    }
    dfs(1, 1);
    for (int i = 1; i <= m; i++) {
        in >> a >> b;
        while (father[a] != father[b]) {
            if (depth[father[a]] > depth[father[b]])
                a = father[a];
            else
                b = father[b];
        }
        while (a != b) {
            if (depth[a] > depth[b])
                a = dad[a];
            else
                b = dad[b];
        }
        out << a << endl;
    }

}