#include <stdio.h>
#include <algorithm>
#include <vector>

#define N 100003
#define T 200005
using namespace std;
int n, m, t[N], f[N], nr, e[T], lg[T], rmq[T][19], h[N];
vector<int> G[N];

void DFS(int s)
{
    e[++nr] = s;
    if (!f[s]) f[s] = nr;
    for (auto x:G[s]) {
        h[x] = h[s] + 1;
        DFS(x);
        e[++nr] = s;
    }
}

void init()
{
    int i, j, p = 1;
    for (i = 1; i <= nr; i++)
        rmq[i][0] = e[i];
    for (j = 1; (p << 1) <= nr; j++, p <<= 1)
        for (i = 1; i <= nr - p + 1; i++)
            if (h[rmq[i][j - 1]] < h[rmq[i + p][j - 1]])
                rmq[i][j] = rmq[i][j - 1];
            else rmq[i][j] = rmq[i + p][j - 1];

    p = 2;
    j = 0;
    for (i = 2; i <= nr; i++) {
        if (i == p) p <<= 1, j++;
        lg[i] = j;
    }
}

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

int main()
{
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    scanf("%i%i", &n, &m);
    int x, y, i;
    for (i = 2; i <= n; i++) {
        scanf("%i", &t[i]);
        G[t[i]].push_back(i);
    }
    DFS(1);
    init();
    for (i = 1; i <= m; i++) {
        scanf("%i%i", &x, &y);
        printf("%i\n", lca(min(f[x], f[y]), max(f[x], f[y])));
    }
    return 0;
}