#include <fstream>
#include <vector>

using namespace std;

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

struct rmqItem {
    int node, lvl;
};

const int DIM = 100010;
const int MAX_LOG = 21;

int n, m, x, y, currPos;
int father[DIM], start[DIM], maxPow[2 * DIM];
rmqItem rmq[MAX_LOG][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 calculateRMQ() {
    for (int pow = 1; pow < MAX_LOG; pow++) {
        for (int i = 1; i <= currPos; i++) {
            rmqItem left = rmq[pow - 1][i];
            if (i + (1 << (pow - 1)) <= currPos) {
                rmqItem right = rmq[pow - 1][i + (1 << (pow - 1))];
                rmq[pow][i] = left.lvl < right.lvl ? left : right;
            } else {
                rmq[pow][i] = left;
            }
        }
    }
}

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

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

    int pow = maxPow[pos2 - pos1 + 1];
    rmqItem left = rmq[pow][pos1];
    rmqItem right = rmq[pow][pos2 - (1 << pow) + 1];

    return (left.lvl < right.lvl ? 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);
    }

    currPos = 0;
    dfs(1, 0);
    calculateRMQ();
    calculateMaxPow();

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

    return 0;
}