#include <fstream>
#include <vector>

using namespace std;

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

int n, q, x, y, ne, e[200005], niv[100005], poz[100005], lca[20][200005], lg[200005];
vector<int> T[100005];

void dfs(int nod) {
    e[++ne] = nod;
    poz[nod] = ne;
    for(auto i : T[nod]) {
        niv[i] = niv[nod] + 1;
        dfs(i);
        e[++ne] = nod;
    }
}

int query(int x, int y) {
    int st = poz[x], dr = poz[y];
    if(st > dr) {
        swap(st, dr);
    }
    int l = lg[dr - st + 1];
    int p = (1 << l);
    x = lca[l][st + p - 1], y = lca[l][dr];
    if(niv[x] > niv[y]) {
        x = y;
    }
    return x;
}

int main() {
    fin >> n >> q;
    for(int i = 1; i < n; i++) {
        fin >> x;
        T[x - 1].push_back(i);
    }
    dfs(0);
    lg[0] = -1;
    for(int i = 1; i <= ne; i++) {
        lg[i] = 1 + lg[i / 2];
        lca[0][i] = e[i];
    }
    for(int i = 1; i <= lg[ne]; i++) {
        for(int j = (1 << i); j <= ne; j++) {
            lca[i][j] = lca[i - 1][j];
            int p = (1 << (i - 1));
            if(niv[lca[i - 1][j - p]] < niv[lca[i - 1][j]]) {
                lca[i][j] = lca[i - 1][j - p];
            }
        }
    }
    for(int i = 1; i <= q; i++) {
        fin >> x >> y;
        fout << query(x - 1, y - 1) + 1 << "\n";
    }
    return 0;
}