#include <bits/stdc++.h>
using namespace std;
 
 
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define pb push_back
#define mp make_pair
#define f first
#define s second

int MAXN = 100001;
vi st(8*MAXN), euler, first(MAXN), height(MAXN);
vector<vi> adj(MAXN);

void dfs(int node, int p, int h){
    height[node] = h;
    first[node] = euler.size();
    euler.pb(node);
    for(auto i : adj[node]){
        if(i != p){
            dfs(i, node, h+1);
            euler.pb(node);
        }
    }
}

void build(int v, int tl, int tr){
    if(tl == tr){
        st[v] = euler[tl];
    } else {
        int tm = (tl+tr)/2;
        build(v*2, tl, tm);
        build(v*2+1, tm+1, tr);
        st[v] = (height[st[v*2]] < height[st[v*2+1]]) ? st[v*2] : st[v*2+1];
    }
}

int minQ(int v, int tl, int tr, int l, int r){
    if(l > r)
        return -1;
    if(tl == l && tr == r)
        return st[v];
    int tm = (tl+tr)/2;
    int left = minQ(2*v, tl, tm, l, min(tm, r));
    int right = minQ(2*v+1, tm+1, tr, max(tm+1, l), r);
    if(left == -1)
        return right;
    if(right == -1)
        return left;
    return (height[left] < height[right]) ? left : right;
}

int update(int v, int tl, int tr, int pos, int new_val){
    if(tl == tr){
        st[v] = new_val;
    } else {
        int tm = (tr+tl)/2;
        if(pos <= tm)
            update(v*2, tl, tm, pos, new_val);
        else
            update(v*2+1, tm+1, tr, pos, new_val);
        st[v] = (height[st[v*2]] < height[st[v*2+1]]) ? st[v*2] : st[v*2+1];
    }
}

void solve(){
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < n-1; i++){
        int x;
        cin >> x;
        adj[x].pb(i+2);
    }
    dfs(1, -1, 1);
    build(1, 0, euler.size()-1);
    for(int i = 0; i < m; i++){
        int a, b;
        cin >> a >> b;
        a = first[a], b = first[b];
        if(a > b)
            swap(a, b);
        cout << minQ(1, 0, euler.size()-1, a, b) << '\n';
    }
}
 
int main(){
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    ios::sync_with_stdio(0); cin.tie(0);
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
}