#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
#define maxn 100010

int N, Q, K;
int H[2*maxn], F[maxn], L[maxn], lvl[maxn], lg[2*maxn];
int RMQ[18][2*maxn];
vector<int> G[maxn];

void Euler(int nod, int niv) {
    H[ ++K ] = nod;
    lvl[nod] = niv;
    F[nod] = K;

    for(vector<int>::iterator it=G[nod].begin(); it!=G[nod].end(); it++) {
         Euler((*it), niv + 1);

         H[ ++K ] = nod;
         L[nod] = K;
    }
}

void make_RMQ() {
    int i, j, p;

    for(i=1; i<=K; i++) {
         RMQ[0][i] = H[i];
    }

    for(i=1; (1 << i) <= K; i++) {
         for(j=1; j<=K; j++) {
              //RMQ[i][j]
              if((1 << i) + j - 1 > K) break;

              if(lvl[ RMQ[i-1][j] ] < lvl[ RMQ[i-1][j + (1 << (i-1))] ]) {
                   RMQ[i][j] = RMQ[i-1][j];
              }
              else {
                   RMQ[i][j] = RMQ[i-1][j + (1 << (i-1))];
              }
         }
    }
}

int LCA(int A, int B) {
    if(F[A] > F[B]) swap(A, B);

    int start = F[A];
    int finish = F[B];
    int idx = lg[finish - start + 1];

    //RMQ[idx][start]
    //RMQ[idx][finish - (1 << (idx)) + 1]
    if(lvl[ RMQ[idx][start] ] < lvl[ RMQ[idx][finish - (1 << idx) + 1] ]) {
         return RMQ[idx][start];
    }
    else {
         return RMQ[idx][finish - (1 << idx) + 1];
    }
}

int main() {
    FILE *f1=fopen("lca.in", "r"), *f2=fopen("lca.out", "w");
    int i, p, q;

    fscanf(f1, "%d %d\n", &N, &Q);
    for(i=1; i<N; i++) {
         fscanf(f1, "%d", &p);
         G[p].push_back(i+1);
    }

    Euler(1, 0);

    make_RMQ();

    lg[1] = 0; //logaritm in baza 2
    for(i=2; i<=K; i++) {
         lg[i] = lg[i / 2] + 1;
    }

    while(Q--) {
         fscanf(f1, "%d %d\n", &p, &q);

         fprintf(f2, "%d\n", LCA(p, q));
    }

    fclose(f1); fclose(f2);
    return 0;
}