#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;

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

int n, m, nivel;

vector<int> v[NMAX];
int v4[NMAX];
vector<int> v2;
vector<int> v3;
int z[20][4*NMAX];

void dfs(int nod)
{
    nivel++;
    for(auto i:v[nod])
    {
        v2.push_back(nod);
        v3.push_back(nivel);
        dfs(i);
    }
    v3.push_back(nivel);
    v2.push_back(nod);
    nivel--;
}


int main()
{
    fin>>n>>m;
    int x;
    for(int i=2; i<=n; i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
    dfs(1);

    int k = v3.size();

    for(int i=0; i<k; i++)
    {
        z[0][i] = i;
    }

    for(int j=1; (1<<j)<k; j++)
    {
        for(int i=0; i+(1<<(j-1))<k; i++)
        {
            z[j][i] = z[j-1][i+(1<<(j-1))];
            if(v2[z[j-1][i]] < v2[z[j-1][i+(1<<(j-1))]])
                z[j][i] = z[j-1][i];
        }
    }

    int y;
    for(int i=0; i<v2.size(); i++)
    {
        v4[v2[i]] = i;
    }

    int j = 0;

    for(int i=0; i<m; i++)
    {
        fin>>x>>y;
        x = v4[x];
        y = v4[y];
        if(x>y)
            swap(x, y);
        j=0;
        while(x+(1<<j)-1<=y)
            j++;
        j--;
        if(z[j][x]<=z[j][y-(1<<j)+1])
            fout<<v2[z[j][x]]<<'\n';
        else
            fout<<v2[z[j][y-(1<<j)+1]]<<'\n';

    }
    return 0;
}