#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

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

int n,m;
vector <int> g[100005];
int adancime[100005], ap[100005];
vector <int> dp[20];

void dfs(int nod, int ad)
{
    adancime[nod] = ad;
    ap[nod]=dp[0].size();
    dp[0].push_back(nod);

    for(int i : g[nod])
    {
        dfs(i,ad+1);
        dp[0].push_back(nod);
    }

}
int main()
{
    in >> n >> m;

    for(int i=2; i<=n; ++i)
    {
        int x;
        in >> x;
        g[x].push_back(i);
    }

    dfs(1,0);

    int len = dp[0].size();

    for(int i = 1; (1<<i) <= len; ++i)
    {
        for(int j = 0; j+(1<<(i-1)) < len; ++j)
            if(adancime[dp[i-1][j]] < adancime[dp[i-1][j+(1<<(i-1))]])
                dp[i].push_back(dp[i-1][j]);
            else
                dp[i].push_back(dp[i-1][j+(1<<(i-1))]);
    }

    for(int i = 0; i < m; ++i)
    {
        int x, y;
        in >> x >> y;
        x=ap[x];
        y=ap[y];
        if(x>y)
            swap(x,y);
        int k = log2(y-x+1);
        if(adancime[dp[k][x]] < adancime[dp[k][y-(1<<(k))+1]])
            out<<dp[k][x];
        else
            out<<dp[k][y-(1<<(k))+1];
        out<<"\n";
    }

    return 0;
}