#include <iostream>
#include <fstream>
#include <vector>
#include <climits>
#include <queue>
#include <cmath>

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

const int NMax = 1e5 + 5;
const int inf = 1e9;

int N,M,nrEuler;
int lg[2*NMax],euler[2*NMax],mn[2*NMax][20],depth[NMax],poz[NMax];

vector<int> v[NMax];

void parcurge(int,int);

int main() {
    in>>N>>M;

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

    parcurge(1,1);

    /*
    for (int i=1;i<=N;++i) {
        out<<i<<' '<<poz[i]<<'\n';
    }
    */

    lg[1] = 0;
    mn[1][0] = euler[1];
    for (int i=2;i<=nrEuler;++i) {
        lg[i] = lg[i/2] + 1;
        mn[i][0] = euler[i];
    }

    for (int p=1;(1<<p) <= nrEuler;++p) {
        for (int i=1;i + (1<<p) - 1 <= nrEuler;++i) {
            int nod1 = mn[i][p-1],
                nod2 = mn[i+(1<<(p-1))][p-1];
            if (depth[nod1] < depth[nod2]) {
                mn[i][p] = nod1;
            }
            else {
                mn[i][p] = nod2;
            }
        }
    }

    while (M--) {
        int a,b;
        in>>a>>b;
        if (poz[a]>poz[b]) {
            swap(a,b);
        }

        int i = poz[a], j = poz[b],
            p = lg[j-i+1];

        int nod1 = mn[i][p],
            nod2 = mn[j - (1<<p) + 1][p];
        if (depth[nod1] < depth[nod2]) {
            out<<nod1<<'\n';
        }
        else {
            out<<nod2<<'\n';
        }
    }

    return 0;
}

void parcurge(int x, int d) {
    depth[x] = d;
    euler[++nrEuler] = x;
    poz[x] = nrEuler;

    for (int k=0;k<v[x].size();++k) {
        parcurge(v[x][k],d+1);

        euler[++nrEuler] = x;
    }
}