#include <fstream>
#include <vector>
#include <bitset>
#include <climits>
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
const int lim=1e5+3,limarb=128024;
vector<int> vec[lim];
bitset<lim> ok;
pair<int,int> tree[2*limarb+3];
int nr=0;
int poz[lim];
int depth[lim];
void add(int k,int x,int y)
{
    k+=limarb;
    tree[k]={x,y};
    for(k/=2;k>0;k/=2)
        tree[k]=min(tree[2*k],tree[2*k+1]);
}
int rasp(int l,int r)
{
    l+=limarb;
    r+=limarb;
    pair<int,int> ans={INT_MAX,0};
    while(l<=r)
    {
        if(l%2==1) ans=min(ans,tree[l++]);
        if(r%2==0) ans=min(ans,tree[r--]);
        l/=2; r/=2;
    }
    return ans.second;
}
void dfs(int nod)
{
    poz[nod]=++nr;
    add(nr,depth[nod],nod);
    ok[nod]=1;
    for(auto x:vec[nod])
    if(!ok[x])
    {
        depth[x]=depth[nod]+1;
        dfs(x);
        poz[nod]=++nr;
        add(nr,depth[nod],nod);
    }
    ok[nod]=0;
}
int main()
{
    int n,q;
    cin>>n>>q;
    for(int i=2;i<=n;++i)
    {
        int x;
        cin>>x;
        vec[x].push_back(i);
    }
    dfs(1);
    while(q--)
    {
        int x,y;
        cin>>x>>y;
        cout<<rasp(min(poz[x],poz[y]),max(poz[x],poz[y]))<<endl;
    }
    return 0;
}