#include <bits/stdc++.h>

#define Nmax 100005
#define LG 20

using namespace std;

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

int N, L, Q, K;
int le[Nmax], ri[Nmax], anc[Nmax][LG];
vector<int> G[Nmax];

bool isAnc(int x, int y) {
    return (le[x] <= le[y] && ri[y] <= ri[x]);
}

int lca(int x, int y) {
    if (isAnc(x, y)) return x;
    if (isAnc(y, x)) return y;
    for (int i = L; i >= 0; --i)
        if (!isAnc(anc[x][i], y)) x = anc[x][i];
    return anc[x][0];
}

void DFS(int node, int father) {
    le[node] = ++K;
    anc[node][0] = father;
    for (int i = 1; i <= L; ++i)
        anc[node][i] = anc[anc[node][i - 1]][i - 1];

    for (auto it: G[node])
        DFS(it, node);
    ri[node] = ++K;
}

int main(){
    f >> N >> Q;
    L = ceil(log2(N));
    for (int i = 2; i <= N; ++i) {
        int x;
        f >> x;
        G[x].push_back(i);
    }

    DFS(1, 1);
    while (Q--) {
        int x, y;
        f >> x >> y;
        g << lca(x, y) << '\n';
    }

    return 0;
}