#include <fstream>
#include <vector>

using namespace std;

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

const int N = 1000100, NM = 22, NA = 2000200;

int n, M, i, j, l, lg[NA], m[NM][NA], x, viz[N], s[NA], t, a, b, dif;
vector<int> v[N];

void dfs(int nod) {
    s[++t] = nod;
    if(!viz[nod]) {
        viz[nod]=t;
    }
    for (int i = 0; i < v[nod].size(); ++i) {
        dfs(v[nod][i]);
        s[++t] = nod;
    }
}

int main() {
    fin >> n >> M;
    for (i = 2; i <= n; ++i) {
        fin >> x;
        v[x].push_back(i);
    }
    dfs(1);
    for (i = 2; i <= t; ++i) {
        lg[i] = lg[(i >> 1)] + 1;
    }
    for (i = 1; i <= t; ++i) {
        m[0][i] = s[i];
    }
    for (i = 1; (1 << i) <= t; ++i) {
        for (j = 1; j <= t - (1 << i); ++j) {
            l = 1 << (i - 1);
            m[i][j] = min(m[i - 1][j], m[i - 1][j + l]);
        }
    }
    for (i = 1; i <= M; ++i) {
        fin >> a >> b;
        a = viz[a];
        b = viz[b];
        if (a > b) {
            swap(a, b);
        }
        dif = b - a + 1;
        l = lg[dif];
        dif = dif - (1 << l);
        fout << min(m[l][a], m[l][a + dif]) << "\n";
    }
    return 0;
}