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

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

int n, m, t[100005], first[100005], lev[100005],rmq[20][300005], logg[300005];
vector<int> g[100005], eul;

void dfs(int x) {
    eul.push_back(x);
    first[x] = eul.size()-1;
    lev[x] = lev[t[x]]+1;
    for(auto next: g[x])
        if(next != t[x]) {
            dfs(next);
            eul.push_back(x);
        }
}

int lca(int x, int y) {
    int a = first[x], b = first[y];
    if(a > b) swap(a, b);

    int lg = logg[b-a+1];
    int ans = rmq[lg][a];
    if(lev[rmq[lg][b-(1<<lg)+1]] < lev[ans])
        ans = rmq[lg][b-(1<<lg)+1];

    return ans;
}

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

    for(int j = 0; j < eul.size(); j++)
        rmq[0][j] = eul[j];

    for(int i = 1; (1<<i) <= eul.size(); i++)
        for(int j = 0; j +(1<<i) <= eul.size(); j++) {
            rmq[i][j] = rmq[i-1][j];
            if(lev[rmq[i-1][j+(1<<(i-1))]] < lev[rmq[i][j]])
                rmq[i][j] = rmq[i-1][j+(1<<(i-1))];
        }
    logg[1] = 0;
    for(int i = 2; i <= eul.size(); i++)
        logg[i] = logg[i/2]+1;

    while(m--) {
        int x, y;
        fin >> x >> y;
        fout << lca(x, y) << '\n';
    }
}