#include <vector>
#include <fstream>
#include <iostream>

using namespace std;

int k,n,m;
int L[200015], H[200015],Lg[200015], First[21];
int Rmq[21][400045];
vector <int> G[21];
vector <int>:: iterator it;

void dfs(int nod, int lev)
{
    H[++k] = nod;
    L[k] = lev;
    First[nod] = k;
    for(it=G[nod].begin();it!=G[nod].end();++it)
    {
        dfs(*it, lev+1);
        H[++k] = nod;
        L[k] = lev;
    }
}

void rmq() {

    for(int i = 2; i <= k; ++i)
        Lg[i] = Lg[i >> 1] + 1;
    for(int i = 1; i <= k; ++i)
        Rmq[0][i] = i;

    for(int i = 1; (1 << i) < k; ++i)
        for(int j = 1; j <= k - (1 << i); ++j)
        {
            int l = 1 << (i - 1);

            Rmq[i][j] = Rmq[i-1][j];
            if(L[Rmq[i-1][j + l]] < L[Rmq[i][j]])
                Rmq[i][j] = Rmq[i-1][j + l];
        }
}

int lca(int x, int y)
{

    int diff, l, sol, sh;
    int a,b;
    a=First[x];
    b = First[y];
    if(a > b) swap(a, b);

    diff = b - a + 1;
    l = Lg[diff];
    sol = Rmq[l][a];
    sh = diff - (1 << l);

    if(L[sol] > L[Rmq[l][a + sh]])
        sol = Rmq[l][a + sh];
    return H[sol];
}

int main() {

    ifstream in("lca.in");
    ofstream out ("lca.out");
    int i,x,y;
    in>>n>>m;

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

    dfs(1, 0);
    rmq();


    for(i=1;i<=m;i++){
        in>>x>>y;
        out<<lca(x, y)<<"\n";
    }

    in.close();
    out.close();
    return 0;
}