#include <fstream>
#include <vector>
#include <iostream>

using namespace std;
const int NMAX = 100001,
          PMAX = 20;
ifstream in("lca.in");
ofstream out("lca.out");

vector<int> C[NMAX];
int L[NMAX << 1], E[NMAX << 1], F[NMAX], lg[NMAX << 1], rmq[PMAX][NMAX << 2],
    K, n, m;

void dfs(int p, int l) {
    E[++K] = p;
    L[K] = l;
    F[p] = K;

    for(const auto& i: C[p]) {
        dfs(i, l+1);

        E[++K] = p;
        L[K] = l;
    }
}

void RMQ() {
    for(int i = 2; i <= K; i++)
        lg[i] = lg[i >> 1] + 1;
    for(int i = 1; i <= K; i++)
        rmq[0][i] = i;

    for(int i = 1; (1 << i) < K; i++) {
        for(int j = 1; j + (1 << i) <= K; j++) {
            int l = 1 << (i-1);

            rmq[i][j] = rmq[i - 1][j];
            if(L[rmq[i - 1][j + l]] < L[rmq[i][j]])
                rmq[i][j] = rmq[i - 1][j + l];
        }
    }
}

int LCA(int x, int y) {
    int dif, l, sol, ad,
        a = F[x], b = F[y];
    if(a > b) swap(a, b);

    dif = b - a + 1;
    l = lg[dif];
    sol = rmq[l][a];
    ad = dif - (1 << l);
    if(L[sol] > L[rmq[l][a + ad]])
        sol = rmq[l][a + ad];
    return E[sol];
}

int main()
{
    in >> n >> m;
    int x;
    for(int i = 2; i <= n; i++) {
        in >> x;
        C[x].push_back(i);
    }
    dfs(1, 0);

    RMQ();

    while(m--) {
        int x, y;
        in >> x >> y;
        out << LCA(x, y) << '\n';
    }
    return 0;
}