#include <fstream>
#include <cmath>
#include <vector>
using namespace std;

ifstream cin("lca.in");
ofstream cout("lca.out");

vector<int> g[100001];
int i,n,q;

vector<int>euler,level,first(100001,0);
vector<int> rmq[20];

void dfs(int nod,int depth)
{
    euler.push_back(nod);
    level.push_back(depth);
    rmq[0].push_back(rmq[0].size());
    for(auto vecin:g[nod])
    {

        dfs(vecin,depth + 1);
        level.push_back(depth);
        euler.push_back(nod);
        rmq[0].push_back(rmq[0].size());
    }
}

int query(int l,int r)
{
    int l2 = log2(r-l+1);

    int rsp = rmq[l2][l];
    if(level[rsp] > level[rmq[l2][r-(1<<(l2))+1]])
        rsp = rmq[l2][r-(1<<(l2))+1];

    return rsp;
}

int main()
{
    cin>>n>>q;
    level.push_back(0);
    euler.push_back(0);
    rmq[0].push_back(0);
    first.resize(n+1,0);
    for(i=1; i<=n-1; i++)
    {
        int elem;
        cin>>elem;
        g[elem].push_back(i+1);

    }
    dfs(1,0);

    for(int p = 1; (1<<p)<=euler.size()-1; p++)
    {
        rmq[p].push_back(0);
        for(i=1; i + (1<<p) -1 <= euler.size()-1; i++)
        {
            rmq[p].push_back(0);
            rmq[p][i] = rmq[p-1][i];
            if(level[rmq[p][i]] > level[rmq[p-1][i+(1<<(p-1))]])
                rmq[p][i] = rmq[p-1][i+(1<<(p-1))];
        }
    }

    for(int i=1; i<euler.size(); i++)
    {
        if(first[euler[i]] == 0)
            first[euler[i]] = i;
    }
    for(int i=1; i<=q; i++)
    {
        int a,b;
        cin>>a>>b;
        int debug = query(min(first[a],first[b]),max(first[a],first[b]));
        cout<<euler[debug]<<'\n';
    }
    return 0;
}