#include <bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
using ll = long long;
#define pb push_back

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

const int N = 2e5+10;

int n, m, k, t[N], niv[N], frst[N], rmq[18][N], query(int,int);
vector<int> fii[N];

void eulerTour(int);

int main()
{
    fin.tie(0); fout.tie(0);
    ios_base::sync_with_stdio(0);
    
    fin >> n >> m;
    for (int i = 2; i <= n; i++) { fin >> t[i]; fii[t[i]].pb(i); }
    eulerTour(1);

    for (int lg = 2, h = 1; lg <= k; lg *= 2, h++)
        for (int i = 1; i + lg - 1 <= k; i++)
            rmq[h][i] = (niv[rmq[h-1][i]] < niv[rmq[h-1][i+lg/2]] ? rmq[h-1][i] : rmq[h-1][i+lg/2]);
    
    while (m--){
        int x, y; fin >> x >> y;
        x = frst[x]; y = frst[y];
        if (x > y) swap(x, y);
        fout << query(x, y) << '\n';
    }

    return 0;
}

void eulerTour(int nod){
    rmq[0][++k] = nod;
    frst[nod] = k;
    for (auto it: fii[nod]){
        niv[it] = niv[nod] + 1;
        eulerTour(it);
        rmq[0][++k] = nod;
    }
}

int query(int l, int r){
    int lg = r - l + 1;
    int pw = 31 - __builtin_clz(lg);
    return (niv[rmq[pw][l]] <  niv[rmq[pw][r-(1<<pw)+1]] ? rmq[pw][l] : rmq[pw][r-(1<<pw)+1]);
}