#include <bits/stdc++.h>
#define ll long long
#define all(a) (a).begin(), (a).end()
//#pragma GCC optimize("O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define sz() size()
#define fr first
#define sc second
#define pb push_back
#define er erase
#define in insert
#define pi pair<int,int>
#define pii pair<pair<int,int>,int>
#define mp make_pair
//#define int long long
#define rc(s) return cout<<s,0
#define rcc(s) cout<<s,exit(0)
using namespace std;

const int mod=1e9+7;
const int modp=1999999973;

int n,m,height[100007],first[100007];
vector<int>euler,nod[100007];
vector<int>tree(100007);

void DFS(int s,int lvl){
    euler.push_back(s);
    first[s]=euler.size()-1;
    height[s]=lvl;
    for(auto it:nod[s]){
        DFS(it,lvl+1);
        euler.push_back(s);
    }
    return;
}

void buildsegtree(int l,int r,int indx){
    if(l==r) tree[indx]=euler[l-1];
    else{
        int mid=l+(r-l)/2;
        buildsegtree(l,mid,2*indx);
        buildsegtree(mid+1,r,2*indx+1);
        tree[indx]= (height[tree[2*indx]]<height[tree[2*indx+1]]) ? tree[2*indx] : tree[2*indx+1];
    }
}

int query(int l,int r,int le,int re,int indx){
    if(re<le) return 100005;
    else if(l>re || r<le) return 100005;
    else if((re>r && le<=r) || (le<l && re>=l)){
        int mid=le+(re-le)/2;
        int x=query(l,r,le,mid,2*indx);
        int y=query(l,r,mid+1,re,2*indx+1);
        return (height[x]<height[y]) ? x : y;
    }
    else return tree[indx];
}

int32_t main(){
 //   ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
    srand(chrono::steady_clock::now().time_since_epoch().count());
    ifstream fin("lca.in");
    ofstream fout("lca.out");
    fin >> n >> m;
    for(int i=1;i<n;i++){
        int x;
        fin >> x;
        nod[x].push_back(i+1);
    }
    DFS(1,0);
    tree.resize(4*euler.size()+20);
    buildsegtree(1,euler.size(),1);
    height[100005]=1e9;
    for(int i=1;i<=m;i++){
        int x,y;
        fin >> x >> y;
        x=first[x]+1;
        y=first[y]+1;
        if(x>y) swap(x,y);
        fout << query(x,y,1,euler.size(),1) << '\n';
    }
    return 0;
}