#include <fstream>
#include <vector>
#define Nmax 100001
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
vector <int> G[Nmax];
int n, x, y, i, Eu[2 * Nmax], Lvl[2 * Nmax], Fst[Nmax], k, log[2 * Nmax], m;
int Rmq[20][4 * Nmax];
void dfs(int nod, int lvl) {
    Eu[++k] = nod;
    Lvl[k] = lvl;
    Fst[nod] = k;
    vector <int> ::iterator  it;
    for(it = G[nod].begin(); it < G[nod].end(); it++) {
        dfs(*it, lvl + 1);
        Eu[++k] = nod;
        Lvl[k] = lvl;
    }
}
void FaRMQ()
{
    log[1] = 0;
    for (int i = 2; i <= k; ++i)
        log[i] = log[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 <= k - (1 << i); ++j) {
            int l = 1 << (i - 1);
            Rmq[i][j] = Rmq[i - 1][j];
            if(Lvl[Rmq[i - 1][j + l]] < Lvl[Rmq[i][j]])
                Rmq[i][j] = Rmq[i - 1][j + l];
        }
}
int lca(int x, int y)
{
    int diff, l, sol, sh;
    int a = Fst[x], b = Fst[y];
    if (a > b) swap(a, b);
    diff = b - a + 1;
    l = log[diff];
    sol = Rmq[l][a];
    sh = diff - (1 << l);
    if(Lvl[sol] > Lvl[Rmq[l][a + sh]])
        sol = Rmq[l][a + sh];
    return Eu[sol];
}
int main() {
    f >> n >> m;
    for (int i = 2; i <= n; i++) {
        f >> x;
        G[x].push_back(i);
    }
    dfs(1, 0);
    FaRMQ();
    for (int i = 1; i <= m; i++) {
        f >> x >> y;
        g << lca(x,y) << '\n';
    }
    return 0;
}