#include <bits/stdc++.h>

using namespace std;

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

const int N_MAX = 100005;

int n, m;
int euler[3 * N_MAX], ne;
int poz[N_MAX], niv[N_MAX];
int dp[30][3 * N_MAX];

vector<int> vec[N_MAX];

void make_euler(int nod, int nivel){
    euler[++ne] = nod;
    niv[ne] = nivel;
    poz[nod] = ne;
    for(auto v : vec[nod]){
        make_euler(v, nivel + 1);
        euler[++ne] = nod;
        niv[ne] = nivel;
    }
}

void rmq(){
    for(int level = 1; level <= log2(ne); ++level)
        for(int j = 1; j<=ne; ++j)
            if(niv[dp[level-1][j]] < niv[dp[level-1][j + (1 << (level-1))]])
                dp[level][j] = dp[level-1][j];
            else
                dp[level][j] = dp[level-1][j + (1 << (level-1))];
}


int query(int a, int b){
    int nivel = log2(b-a+1);
    if(niv[dp[nivel][a]] <= niv[dp[nivel][b - (1 << nivel) + 1]])
        return dp[nivel][a];
    else
        return dp[nivel][b-(1<<nivel) + 1];
}

int lca(int a, int b){
    int lo = min(a, b);
    int hi = max(a, b);
    return euler[query(lo, hi)];
}

int main()
{
    fin >> n >> m;
    for(int i = 2, x; i<=n; ++i){
        fin >> x; vec[x].push_back(i);
    }
    make_euler(1, 0);
    for(int i = 1; i <=ne; ++i)
        dp[0][i] = i;
    rmq();

    while(m--){
        int a, b; fin >> a >> b;
        fout << lca(poz[a],poz[b]) << "\n";
    }
    return 0;
}