#include <bits/stdc++.h>

#define N 100005
using namespace std;
int n, m, t[N], e[2 * N], nr, h[N], r[N][30], lg[2 * N], f[N];
bool o[N];
vector<int> G[N];

void DFS(int s)
{
    int i;
    o[s] = 1;
    e[++nr] = s;
    f[s] = nr;
    for (i = 0; i < G[s].size(); i++)
        if (!o[G[s][i]]) {
            h[G[s][i]] = h[s] + 1;
            DFS(G[s][i]);
            e[++nr] = s;
        }
}

void rmq()
{
    int i, j, p = 1;
    for (i = 1; i <= nr; i++) r[i][0] = e[i];

    for (j = 1; 2 * p <= nr; j++, p <<= 1)
        for (i = 1; i <= nr - 2 * p + 1; i++)
            if (h[r[i][j - 1]] < h[r[i + p][j - 1]])
                r[i][j] = r[i][j - 1];
            else r[i][j] = r[i + p][j - 1];


    j = -1;
    p = 1;
    for (i = 1; i <= nr; i++) {
        if (i == p) j++, p <<= 1;
        lg[i] = j;
    }

}

int query(int x, int y)
{
    int l = lg[y - x + 1];
    if (h[r[x][l]] < h[r[y - (1 << l) + 1][l]]) return r[x][l];
    return r[y - (1 << l) + 1][l];
}

int main()
{
    int i;
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    scanf("%i%i", &n, &m);
    for (i = 2; i <= n; i++) {
        scanf("%i", &t[i]);
        G[t[i]].push_back(i);
    }

    DFS(1);
    rmq();

    int x, y;
    while (m--) {
        scanf("%i%i", &x, &y);
        printf("%i\n", query(min(f[x], f[y]), max(f[x], f[y])));
    }
    return 0;
}