#include <bits/stdc++.h>
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
const int lim=1e5+4;
pair<int,int> tree[19][2*lim];
vector<int> vec[lim];
int lg[2*lim],cnt;
int poz[lim];
int n,m,x,y;
void pre(int nod,int h)
{
    poz[nod]=++cnt;
    tree[0][cnt]={h,nod};
    for(int x:vec[nod])
    {
        pre(x,h+1);
        poz[nod]=++cnt;
        tree[0][cnt]={h,nod};
    }
}
void rmq()
{
    for(int i=2;i<=cnt;++i)
        lg[i]=lg[i/2]+1;
    for(int p=1;p<=lg[cnt];++p)
    for(int i=1;i+(1<<p)-1<=cnt;++i)
        tree[p][i]=min(tree[p-1][i],tree[p-1][i+(1<<(p-1))]);
}
int lca(int x,int y)
{
    x=poz[x],y=poz[y];
    if(x>y) swap(x,y);
    int d=lg[y-x+1];
    return min(tree[d][x],tree[d][y-(1<<d)+1]).second;
}
int main()
{
    in>>n>>m;
    for(int i=2;i<=n;++i)
        in>>x,
        vec[x].push_back(i);
    pre(1,0);
    rmq();
    for(int i=1;i<=m;++i)
        in>>x>>y,
        out<<lca(x,y)<<'\n';
    return 0;
}