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

ifstream cin("lca.in");
ofstream cout("lca.out");

int mar[100001];
int par[100001];
int heavy[100001];
int tp[100001];
int nr[100001];
int adan[100001];
int adan1[100001];
int cnt;
vector<int> aux;
int bl[100001][21];
vector<int> v[100001];

void dfs(int tata,int nod){
    mar[nod]=1;
    for(auto it:v[nod]){
        if(it==tata) continue;
        adan[it]=adan[nod]+1;
        par[it]=nod;
        dfs(nod,it);
        mar[nod]+=mar[it];

        if(mar[it]>mar[heavy[nod]]) heavy[nod]=it;
    }
}

void dfs1(int tata,int nod,int top){

    nr[nod]=cnt;cnt++;
    tp[nod]=top;
    if(!heavy[nod]) return;
    dfs1(nod,heavy[nod],top);
    for(auto it:v[nod]){
        if(it==tata || it==heavy[nod]) continue;
        bl[it][0]=top;adan1[it]=adan1[top]+1;
        aux.push_back(it);
        dfs1(nod,it,it);
    }
}

pair<int,int> lca1(int a,int b){
    if(adan1[b]<adan1[a]) swap(a,b);
    int i;
    for(i=19;i>=0;i--){
        if(adan1[bl[b][i]]>=adan1[a]) b=bl[b][i];
    }
    for(i=19;i>=0;i--){
        if(bl[b][i]!=bl[a][i]){
            b=bl[b][i];
            a=bl[a][i];
        }
    }
    return {a,b};

}

int lca(int a,int b){
    if(tp[a]!=tp[b]){
        pair<int,int> aux={a,b};
        a=aux.first;b=aux.second;
    }
    if(a>b) swap(a,b);
    while(tp[a]!=tp[b]){
        if(adan[tp[a]]<adan[tp[b]]) b=par[tp[b]];
        else a=par[tp[a]];
    }
    if(adan[a]<adan[b]) return a;
    return b;
}

int main()
{
    int n,m,i,a,b;
    cin>>n>>m;
    for(i=2;i<=n;i++){
        cin>>a;
        v[a].push_back(i);
    }
    par[1]=1;
    dfs(1,1);
    dfs1(1,1,1);
    for(i=1;i<20;i++){
        for(auto it:aux){
            bl[it][i]=bl[bl[it][i-1]][i-1];
        }
    }
    for(i=1;i<=m;i++){
        cin>>a>>b;
        cout<<lca(a,b)<<"\n";
    }
    return 0;
}