#include <bits/stdc++.h>

using namespace std;

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

int n, m;
vector<int> g[100100];
int nivel[100100];
int euler[200200], cnt, st[200200];
int logaritm[200200];
int rmq[200200][19];

void dfs(int fiu, int tata)
{
    nivel[fiu] = 1 + nivel[tata];
    euler[++cnt] = fiu;
    for(auto it : g[fiu])
    {
        if(it == tata)
        {
            continue;
        }
        dfs(it, fiu);
        euler[++cnt] = fiu;
    }
}

int lca(int x, int y)
{
    if(st[x] > st[y])
        swap(x, y);
    int logg = logaritm[st[y] - st[x] + 1];
    int a = rmq[st[x]][logg];
    int b = rmq[st[y] - (1 << logg) + 1][logg - 1];
    if(nivel[a] < nivel[b])
        return a;
    else
        return b;
}

int main()
{
    fin >> n >> m;
    for(int i = 2; i <= 2 * n; i ++)
    {
        logaritm[i] = logaritm[i / 2] + 1;
    }
    for(int i = 2; i <= n; i ++)
    {
        int val;
        fin >> val;
        g[val].push_back(i);
    }
    dfs(1, 0);
    for(int i = 1; i <= cnt; i ++)
    {
        rmq[i][0] = euler[i];
        if(st[euler[i]] == 0)
        {
            st[euler[i]] = i;
        }
    }
    for(int j = 1; (1 << j) <= cnt; j ++)
    {
        for(int i = 1; i + (1 << j) - 1 <= cnt; i ++)
        {
            int a = rmq[i][j - 1];
            int b = rmq[i + (1 << (j - 1))][j - 1];
            if(nivel[a] < nivel[b])
                rmq[i][j] = a;
            else
                rmq[i][j] = b;
        }
    }
    while(m--)
    {
        int x, y;
        fin >> x >> y;
        fout << lca(x, y) << '\n';
    }
}