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#include <iostream>
#include <vector>

using namespace std;
typedef long long ll;
const int maxn = 2e5 + 10;
const int logn = 18;
int parent[maxn][logn];
vector<int> depth(maxn, 0);
vector<int> graph[maxn];
int timer = 0;
int in_time[maxn], out_time[maxn];
void dfs(int node, int prev) {
    timer++;
    in_time[node] = timer;
    parent[node][0] = prev;
    for(int i = 1; i < logn; i++) {
        parent[node][i] = parent[parent[node][i - 1]][i - 1];
    }
    for(int neighbour : graph[node]) {
        if(prev != neighbour) {
            dfs(neighbour, node);
        }
    }

timer++;
    out_time[node] = timer;
}
bool is_ancestor(int a, int b) {
    return (in_time[a] <= in_time[b] and out_time[a] >= out_time[b]);
}
int LCA(int a, int b) {
    if(is_ancestor(a, b)) {
        return a;
    }
    if(is_ancestor(b, a)) {
        return b;
    }
    for(int i = logn - 1; i >= 0; i--) {
        if(!is_ancestor(parent[a][i], b)) {
            a = parent[a][i];
        }
    }
    return parent[a][0];
}

int main() {
    int n, q;
    cin >> n >> q;
    vector<int> tree(n + 1, -1);
    
    for(int i = 2; i <= n; i++) {
        cin >> tree[i];
        graph[i].push_back(tree[i]);
        graph[tree[i]].push_back(i);
        parent[i][0] = tree[i];
    }
    parent[1][0] = -1;
    dfs(1, 1);
    while(q--) {
        int a, b;
        cin >> a >> b;
        cout << LCA(a, b) << endl;
    }
    return 0;
}