#include <fstream>
#include <vector>

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

const int nmax = 130005;
int eul[2*nmax+5], rmq[20][2*nmax+5], m, n, i, j, x, y, ne, fst[nmax], niv[nmax], log2[nmax];
vector <int> ls[nmax];

void dfs(int x) {
    int l = ls[x].size(), i, y;
    eul[++ne] = x;
    fst[x] = ne;
    for (i = 0; i < l; i++) {
        y = ls[x][i];
        niv[y] = niv[x] + 1;
        dfs(y);
        eul[++ne] = x;
    }
}

void RMQ() {
    int i, j, lft, rgt;
    for (i = 1; i <= ne; i++)
        rmq[0][i] = eul[i], log2[i+1] = log2[(i+1)/2]+1;

    for (i = 1; (1 << i) <= ne; i++)
        for (j = 1; j+(1<<i)-1 <= ne; j++) {
            lft = rmq[i-1][j];
            rgt = rmq[i-1][j+(1<<(i-1))];
            if (niv[lft] < niv[rgt])
                rmq[i][j] = lft;
            else rmq[i][j] = rgt;
        }
}

int query(int x, int y) {
    int lft = fst[x], rgt = fst[y];
    if (lft > rgt) {
        swap(lft, rgt);
        swap(x, y);
    }
    int dif = rgt-lft+1;
    int i = log2[dif];
    int xx = rmq[i][lft], yy = rmq[i][rgt-(1<<i)+1];
    if (niv[xx] < niv[yy])
        return xx;
    else return yy;
}

int main() {
    f >> n >> m;
    for (i = 2; i <= n; i++) {
        f >> x;
        ls[x].push_back(i);
    }
    niv[x] = 1;
    dfs(1);
    RMQ();
    while (m--) {
        f >> x >> y;
        g << query(x, y) << '\n';
    }
    return 0;
}