#include <bits/stdc++.h>
#define NMAX 100005

using namespace std;

FILE*f=fopen("lca.in","r");
FILE*g=fopen("lca.out","w");

vector<int> v[NMAX];
int niv[2*NMAX][20],m,n,nr,euler[2*NMAX],a[2*NMAX],niv2[2*NMAX];

void df(int k,int nivel) {
    int i;
    niv[++nr][0]=k;
    euler[nr]=k;
    if (!niv2[k]) niv2[k]=nivel;
    if (!a[k]) a[k]=nr;
    for (i=0;i<v[k].size();i++) {
//        if (!viz[v[k][i]]) {
            df(v[k][i],nivel+1);
            niv[++nr][0]=k;
            euler[nr]=k;
        }
}

int query(int x,int y) {
    if (x>y) swap(x,y);
    int k=log2(y-x+1);
    if (niv2[niv[x][k]]<niv2[niv[y-(1<<k)+1][k]]) return niv[x][k];
    return niv[y-(1<<k)+1][k];
}

int main() {
    int i,j,x,y;
    fscanf(f,"%d%d",&n,&m);
    for (i=2;i<=n;i++) {
        fscanf(f,"%d",&x);
        v[x].push_back(i);
    }
    df(1,0);
    for (i=1;(1<<i)<=nr;i++)
        for (j=1;j+(1<<i)-1<=nr;j++)
            if (niv2[niv[j][i-1]]<niv2[niv[j+(1<<(i-1))][i-1]]) niv[j][i]=niv[j][i-1];
            else niv[j][i]=niv[j+(1<<(i-1))][i-1];
    /*for (i=1;i<=nr;i++) cout<<niv2[i]<<' ';
    cout<<'\n';
    for (i=1;i<=nr;i++) cout<<euler[i]<<' ';
    cout<<'\n';
    for (i=1;i<=nr;i++) cout<<a[i]<<' ';
    cout<<'\n';
    cout<<'\n';
    for (i=1;i<=nr;i++) {
        for (j=0;j<20;j++) cout<<niv[i][j]<<' ';
        cout<<'\n';
    }*/
    for (i=1;i<=m;i++) {
        fscanf(f,"%d%d",&x,&y);
        fprintf(g,"%d\n",query(a[x],a[y]));
    }
    return 0;
}