#include <bits/stdc++.h>

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

vector<int>v[100001];
pair<int,int>rmq[800001][21];
int n,pr[100001];

void citeste();
void dfs(int nod,int grad)
{
    rmq[++n][0].first = grad;
    rmq[n][0].second = nod;
    if(v[nod].size()==0)
    {
        return;
    }
    for(int i = 0; i < v[nod].size(); ++i)
        if(!pr[v[nod][i]])
        {
            pr[v[nod][i]] = n + 1;
            dfs(v[nod][i],grad + 1);
            rmq[++n][0].first = grad;
            rmq[n][0].second = nod;
        }
}
void rmq_c()
{
    int k=log2(n);
    for(int j = 1; j <= k+1; ++j)
        for(int i = 1; i <= n - (1 << j) + 1; ++i)
        {
            int x = rmq[i][j - 1].first;
            int y = rmq[i][j - 1].second;
            int x2 = rmq[i + (1 << (j - 1))][j - 1].first;
            int y2 = rmq[i + (1 << (j - 1))][j - 1].second;
            if(x<x2)
                rmq[i][j] = {x,y};
            else rmq[i][j] = {x2,y2};
        }
}

int main()
{
    int n,m;
    f >> n >> m;
    for(int i = 2; i <= n; ++i)
    {
        int a;
        f >> a;
        v[a].push_back(i);
    }
    pr[1] = 1;
    dfs(1,0);
    rmq_c();
    while(m--)
    {
        int st,dr;
        f >> st >> dr;
        st = pr[st];
        dr = pr[dr];
        if(st > dr)
            swap(st,dr);
        int k = log2(dr - st + 1);
        int x = rmq[st][k].first;
        int y = rmq[st][k].second;
        int x2 = rmq[dr - (1 << k) + 1][k].first;
        int y2 = rmq[dr - (1 << k) + 1][k].second;
        if(x<x2)
            g << y << '\n';
        else g << y2 << '\n';
    }
    return 0;
}