#include <stdio.h>
#include <algorithm>
#include <vector>
#define nmax 100010
#define pmax 230010
using namespace std;
struct date { int niv,nod; };
int n,m,i,j,x,y,tata[nmax],v[pmax],pos[nmax],nr=0,aux;
vector <int> g[nmax];
date rmq[18][pmax];
inline date min(date a,date b) {
    if (a.niv<b.niv) return a; else return b;
}
void euler(int nod,int h)
{
    nr++; rmq[0][nr].niv=h; rmq[0][nr].nod=nod; pos[nod]=nr;
    for (unsigned int i=0;i<g[nod].size();i++) {
        euler(g[nod][i],h+1);
        nr++; rmq[0][nr].niv=h; rmq[0][nr].nod=nod;
    }
}
int query(int x,int y)
{
    int d=v[y-x+1],aux; aux=1<<d;
    return min(rmq[d][x],rmq[d][y-aux+1]).nod;
}
int main() {
freopen("lca.in","r",stdin);
freopen("lca.out","w",stdout);
scanf("%d %d",&n,&m);
for (i=2;i<=n;i++) { scanf("%d",&x); g[x].push_back(i); }
euler(1,0); v[1]=0;
for (i=2;i<=nr;i++) v[i]=v[i/2]+1;
for (i=1;1<<i<=nr;i++) {
    aux=1<<(i-1);
    for (j=1;j+aux<=nr;j++)
        rmq[i][j]=min(rmq[i-1][j],rmq[i-1][j+aux]);
}
for (i=1;i<=m;i++) {
    scanf("%d %d",&x,&y); x=pos[x]; y=pos[y];
    if (x>y) swap(x,y);
    printf("%d\n",query(x,y));
}
return 0;
}