#include <bits/stdc++.h>
using namespace std;

const int N = 1e6 + 5, LG = 20;

int v[N], dp[LG][N];
int f[N];
vector <int> g[N];

void dfs(int n) {
    for (auto i : g[n]) {
        if (v[i] == 0) {
            f[i] = f[n] + 1;
            v[i] = n;
            dfs(i); } } }

int main() {
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    int n, m, x, y, p, q, r;

    scanf("%d %d", &n, &m);
    for (int i = 2; i <= n; i++) {
        scanf("%d", &x);
        g[x].push_back(i);
        g[i].push_back(x); }

    f[1] = 1;
    v[1] = -1;
    dfs(1);
    v[1] = 0;

    for (int i = 1; i <= n; i++)
        dp[0][i] = v[i];

    for (int lg = 1; lg < LG; lg++)
        for (int nod = 1; nod <= n; nod++)
            dp[lg][nod] = dp[lg - 1][dp[lg - 1][nod]];

    for (int i = 1; i <= m; i++) {
        scanf("%d %d", &x, &y);
        if (f[x] > f[y])
            swap(x, y);

        r = f[y] - f[x];
        p = 0;
        while (r) {
            if (r % 2 == 1)
                y = dp[p][y];
            p+= 1;
            r = r / 2; }

        for (int p = LG - 1; p >= 0; p--) {
            if (dp[p][x] != dp[p][y]) {
                x = dp[p][x];
                y = dp[p][y]; } }

        if (x == y)
            printf("%d\n", x);
        else
            printf("%d\n", v[x]); }

    return 0; }