#include <fstream>
#include <vector>

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

const int DIM = 100010;
const int LOG = 21;

struct rmqItem {
    int node, level;
} rmq[LOG][2 * DIM];

int n, m, x, y;
int currPos = 0;
int father[DIM], start[DIM], exp[2 * DIM];
vector<int> l[DIM];

void dfs(int node, int lvl) {
    rmq[0][++currPos] = { node, lvl };
    start[node] = currPos;
    for (auto son : l[node]) {
        dfs(son, lvl + 1);
        rmq[0][++currPos] = { node, lvl };
    }
}

void calcRMQ() {
    for (int p = 1; p < LOG; p++) {
        for (int i = 1; i <= currPos; i++) {
            rmqItem left = rmq[p - 1][i];
            if (i + (1 << (p - 1)) <= currPos) {
                rmqItem right = rmq[p - 1][i + (1 << (p - 1))];
                rmq[p][i] = (left.level < right.level ? left : right);
            } else {
                rmq[p][i] = left;
            }
        }
    }
}

void calcMaxExp() {
    exp[1] = 0;
    for (int i = 2; i <= currPos; i++)
        exp[i] = 1 + exp[i / 2];
}

int getLCA(int node1, int node2) {
    int pos1 = start[node1];
    int pos2 = start[node2];
    if (pos1 > pos2) swap(pos1, pos2);

    int currExp = exp[pos2 - pos1 + 1];
    int pow = (1 << currExp);
    rmqItem left = rmq[currExp][pos1];
    rmqItem right = rmq[currExp][pos2 - pow + 1];
    return (left.level < right.level ? left.node : right.node);
}

int main() {
    fin >> n >> m;
    for (int i = 2; i <= n; i++) {
        fin >> father[i];
        l[father[i]].push_back(i);
    }

    dfs(1, 0);
    calcRMQ();
    calcMaxExp();

    for (int i = 1; i <= m; i++) {
        fin >> x >> y;
        fout << getLCA(x, y) << '\n';
    }

    return 0;
}