#include <iostream>
#include <vector>
using namespace std;

vector<int> G[100001];
bool viz[100001];
int H[200002], poz[200002], k, rmq[18][200002], L[200002], lg[200002];

void DFS(int nod, int lev) {
    //parcurgere Euler
    //nodurile sunt stocate in H[ ] si prima pozitia pe care apar ele in poz[ ]
    if(viz[nod]) { return; }
    viz[nod]=1;
    H[++k]=nod;
    L[k]=lev;
    poz[nod]=k;
    for(vector<int>::iterator it=G[nod].begin(); it!=G[nod].end(); it++) {
         DFS(*it, lev+1);
         H[++k]=nod;
         L[k]=lev;
    }
}

int main() {
    FILE *f1=fopen("lca.in", "r"), *f2=fopen("lca.out", "w");
    int n, m, i, j, p, q, x, y, aux;
    int sol;
    fscanf(f1, "%d%d", &n, &m);
    for(i=2; i<=n; i++) {
         fscanf(f1, "%d", &p);
         G[p].push_back(i);
    }
    DFS(1, 0);
    lg[1]=0;
    for(i=2; i<=k; i++) {
         lg[i]=lg[i >> 1] + 1;
    }
    for(i=1; i<=k; i++) {
         rmq[0][i]=i;
    }
    for(i=1; (1<<i)<k; ++i) {
         for(j=1; j<=k-(1 << i); ++j) {
              int l = 1 << (i - 1);
              rmq[i][j]=rmq[i-1][j];
              if(L[rmq[i-1][j+l]]<L[rmq[i][j]]) {
                   rmq[i][j] = rmq[i-1][j+l];
              }
         }
    }
    for(i=1; i<=m; i++) {
         fscanf(f1, "%d%d", &p, &q);
         //returneaza minimul secventei dintre poz[p], poz[q];
         p=poz[p]; q=poz[q];
         if(p>q) { swap(p, q); }
         //(int)(floor(log2((double)(n))));
         x=lg[q-p+1];
         aux=q-p+1-(1 << x);
         //rmq[x][p], rmq[x][p+aux]
         sol=rmq[x][p];
         if(L[sol]>L[rmq[x][p+aux]]) {
              sol=rmq[x][p+aux];
         }
         fprintf(f2, "%d\n", H[sol]);
    }
    fclose(f1); fclose(f2);
    return 0;
}