#include<bits/stdc++.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <int, pi>
#define vi vector <int>
const ll mod = 1e9 + 7;
int n, timer, in[100001], out[100001], mx, up[100001][23], q;
vi g[100001];

void dfs(int nod, int p){
    in[nod]=++timer;
    up[nod][0]=p;
    for(int i=1; i<=mx; i++) up[nod][i]=up[up[nod][i-1]][i-1];
    for(int i: g[nod]){
        if(i!=p){
            dfs(i, nod);
        }
    }
    out[nod]=++timer;
}

bool check(int nod1, int nod2){
    if(in[nod1]<=in[nod2] && out[nod2]<=out[nod1]) return true;
    else return false;
}

int lca(int l, int r){
    if(check(l, r)) return l;
    else if(check(r, l)) return r;
    for(int i=mx; i>=0; i--){
        if(check(up[l][i], r)==0) l=up[l][i];
    }
    return up[l][0];
}

int32_t main(){
    ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    cin>>n>>q;
    for(int i=2; i<=n; ++i){
        int x;
        cin>>x;
        g[x].pb(i);
        g[i].pb(x);
    }
    mx=ceil(log2((double)n));
    dfs(1, 1);
    while(q--){
        int l, r;
        cin>>l>>r;
        cout<<lca(l, r)<<"\n";
    }
}