#include <bits/stdc++.h>

#define ff first

#define ss second



using namespace std;

typedef long long ll;

typedef long double ld;

typedef pair<int, int> pi;

typedef pair<ll, ll> pll;

typedef pair<ld, ld> pld;



const string file = "lca";

const ll INF = 9223372036854775807ll;

const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, inf = 2147483647, nmax = 100005;



int n, test, p, dep[nmax], first[nmax], lg2[nmax*2];

vector<int> v[nmax];

pi pd[20][nmax*2];



void dfs(int nod, int pred)

{

    dep[nod] = dep[pred]+1;

    pd[0][++p] = {dep[nod], nod};

    first[nod] = p;

    for (auto x : v[nod])

        if(x != pred){

            dfs(x, nod);

            pd[0][++p] = {dep[nod], nod};

        }

}



int query(int a, int b)

{

    if(a == b)

        return a;

    a = first[a];

    b = first[b];

    if(a > b)

        swap(a, b);

    int len = lg2[b-a+1];

    return min(pd[len][a], pd[len][b-(1<<len)+1]).ss;

}



int main()

{

    ifstream fin (file+".in");

    ofstream fout (file+".out");

    fin >> n >> test;

    for (int i = 2; i <= n; ++i){

        int x;

        fin >> x;

        v[x].push_back(i);

        v[i].push_back(x);

    }

    dfs(1, 0);

    for (int i = 2; i < nmax*2; ++i)

        lg2[i] = lg2[i/2]+1;

    for (int t = 1; (1<<t) <= p; ++t)

        for (int i = 1; i+(1<<t)-1 <= p; ++i)

            pd[t][i] = min(pd[t-1][i], pd[t-1][i+(1<<(t-1))]);

    while(test--){

        int a, b;

        fin >> a >> b;

        fout << query(a, b) << "\n";

    }

    return 0;

}