#include <iostream>
#include <fstream>
#include <cstdlib>
#include <vector>

using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");

#define ll long long
#define pb push_back
#define ui unsigned int
const int inf = 1e9 + 5;
const int NMax = 1e5 + 5;

int N,M,nrEuler;
int dad[NMax],depth[NMax],idx[NMax],euler[2*NMax],lg[2*NMax],rmq[2*NMax][20];
vector<int> v[NMax];

void build(int);

int main() {
    in>>N>>M;
    for (int i=2;i <= N;++i) {
        in>>dad[i];

        v[dad[i]].pb(i);
    }

    build(1);

    lg[1] = 0;
    rmq[1][0] = 1;
    //cout<<euler[1]<<' ';
    for (int i=2;i <= nrEuler;++i) {
        lg[i] = lg[i/2] + 1;
        rmq[i][0] = euler[i];

        //cout<<euler[i]<<' ';
    }

    for (int p=1;(1<<p) <= nrEuler;++p) {
        for (int i=1;i + (1<<p) - 1 <= nrEuler;++i) {
            int node1 = rmq[i][p-1],
                node2 = rmq[i + (1<<(p-1))][p-1];

            if (depth[node1] < depth[node2]) {
                rmq[i][p] = node1;
            }
            else {
                rmq[i][p] = node2;
            }
        }
    }

    while (M--) {
        int a,b;
        in>>a>>b;

        a = idx[a];
        b = idx[b];
        if (a > b) {
            swap(a,b);
        }

        int pw = lg[b-a+1];
        int node1 = rmq[a][pw],
            node2 = rmq[b - (1<<pw) + 1][pw];
        if (depth[node1] < depth[node2]) {
            out<<node1<<'\n';
        }
        else {
            out<<node2<<'\n';
        }
    }

    in.close();out.close();
    return 0;
}

void build(int node) {
    depth[node] = depth[dad[node]] + 1;
    euler[++nrEuler] = node;
    idx[node] = nrEuler;

    for (auto nxt : v[node]) {
        /*
        if (depth[nxt]) {
            continue;
        }
        //*/

        build(nxt);
        euler[++nrEuler] = node;
    }
}