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

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

int n, m, t[100005], lev[100005], first[100005], logg[400005], rmq[400005][20];
vector<int> g[100005];
vector<int> 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(b < a) swap(a, b);
    int lg = logg[b-a+1];
    int ans = rmq[a][lg];
    if(lev[rmq[b-(1<<lg)+1][lg]] < lev[ans])
        ans = rmq[b-(1<<lg)+1][lg];
    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);
    int l = eul.size();
    logg[1] = 0;
    for(int i = 2; i <= l; i++)
        logg[i] = logg[i/2]+1;

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


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


}