#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <cstdlib>
#include <ctime>

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

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

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

void dfs(int);

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

    dfs(1);

    lg[1] = 0;
    rmq[1][0] = euler[1];
    for (int i=2;i <= nrEuler;++i) {
        lg[i] = lg[i/2] + 1;
        rmq[i][0] = 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 x,y;
        in>>x>>y;

        x = pos[x];
        y = pos[y];
        if(x > y) {
            swap(x,y);
        }

        int p = lg[y-x+1],
            node1 = rmq[x][p],
            node2 = rmq[y - (1<<p) + 1][p];

        out<<( (depth[node1] < depth[node2]) ? node1 : node2)<<'\n';
    }

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

void dfs(int node) {
    euler[++nrEuler] = node;
    pos[node] = nrEuler;

    for (int nxt : v[node]) {
        if (depth[nxt]) {
            continue;
        }

        depth[nxt] = depth[node] + 1;
        dfs(nxt);
        euler[++nrEuler] = node;
    }
}