#include <bits/stdc++.h>
using namespace std;
const int N = 100010;
ifstream f("lca.in");
ofstream g("lca.out");
int n, m, k, st, dr, mi, deep[N], start[N], e[18][2 * N];
vector <int> v[N];
void dfs(int, int);
int main()
{
    f >> n >> m;
    for(int i = 2; i <= n; i++)
    {
        int x;
        f >> x;
        v[x].push_back(i);
    }
    dfs(1, 1);
    for(int i = 1, p = 1, P = 2; P <= k; p *= 2, P *= 2, i++)
        for(st = 1, mi = p + 1, dr = P; dr <= k; dr++, st++, mi++)
            e[i][st] = deep[e[i - 1][st]] < deep[e[i - 1][mi]]?e[i - 1][st]:e[i - 1][mi];
    for(; m; m--)
    {
        int x, y;
        f >> x >> y;
        x = start[x];
        y = start[y];
        if(x > y)
            swap(x, y);
        int i = 31 - __builtin_clz(y - x + 1);
        int p = 1 << i;
        y = y - p + 1;
        x = e[i][x];
        y = e[i][y];
        x = deep[x] < deep[y] ? x:y;
        g << x << '\n';
    }

    return 0;
}
void dfs(int nod, int niv)
{
    e[0][++k] = nod;
    start[nod] = k;
    deep[nod] = niv;
    for(auto it:v[nod])
    {
        dfs(it, niv + 1);
       e[0][++k] = nod;
    }
}