#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)
///#define cin fin
///#define cout fout
using namespace std;

const int mod=1e9+7;

int n,m,x,y,lca[100005][18],tin[100005],tout[100005],timcurr;
vector<int>nod[100005];

void DFS(int s,int par){
    timcurr++;
    tin[s]=timcurr;
    int curr=par;
    lca[s][0]=par;
    for(int i=1;i<=17;i++){
        lca[s][i]=lca[lca[s][i-1]][i-1];
    }
    for(auto it:nod[s]){
        if(it!=par) { DFS(it,s); timcurr++; }
    }
    tout[s]=timcurr;
}

int32_t main(){
    ifstream fin("lca.in");
    ofstream fout("lca.out");
	//ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
    srand(chrono::steady_clock::now().time_since_epoch().count());
    fin >> n >> m;
    for(int i=1;i<n;i++){
        fin >> x;
        nod[x].push_back(i+1);
        nod[i+1].push_back(x);
    }
    DFS(1,0);
    for(int i=1;i<=m;i++){
        fin >> x >> y;
        if(tin[y]<tin[x] && tout[y]>tout[x]) fout << y << '\n';
        else if(tin[x]<tin[y] && tout[x]>tout[y]) fout << x << '\n';
        else{
            while(true){
                int nod=x;
                for(int j=0;j<=17;j++){
                    if((tin[lca[nod][j]]>tin[y] || tout[lca[nod][j]]<tout[y]) && lca[nod][j]!=0){
                        if((tin[lca[nod][j+1]]<tin[y] && tout[lca[nod][j+1]]>tout[y]) && lca[nod][j+1]!=0){
                            nod=lca[nod][j];
                            break;
                        }
                    }
                }
                if(tin[lca[nod][0]]<tin[y] && tout[lca[nod][0]]>tout[y]){
                    fout << lca[nod][0] << '\n';
                    break;
                }
            }
        }
    }
}