#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ull unsigned ll
#define vec vector
#define flist forward_list
#define um unordered_map
#define us unordered_set
#define prioq priority_queue
#define all(x) x.begin(), x.end()
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define ld long double
#define pll pair<ll, ll>
#define tll tuple<ll, ll, ll>
#define ass assign

#define LL_MAX LLONG_MAX
#define LL_MIN LLONG_MIN
#define ULL_MAX ULLONG_MAX
#define LD_MAX LDBL_MAX
#define LD_MIN LDBL_MIN

#define nl '\n'

#define vv(type, name, n, ...) vector<vector<type>> name(n, vector<type>(__VA_ARGS__))
#define vvv(type, name, n, m, ...)                                                                                     \
    vector<vector<vector<type>>> name(n, vector<vector<type>>(m, vector<type>(__VA_ARGS__)))

// https://trap.jp/post/1224/
#define rep1(n) for(ll i=0; i<(ll)(n); ++i)
#define rep2(i,n) for(ll i=0; i<(ll)(n); ++i)
#define rep3(i,a,b) for(ll i=(ll)(a); i<(ll)(b); ++i)
#define rep4(i,a,b,c) for(ll i=(ll)(a); i<(ll)(b); i+=(c))
#define cut4(a,b,c,d,e,...) e
#define rep(...) cut4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define rep1e(n) for(ll i=1; i<=(ll)(n); ++i)
#define rep2e(i,n) for(ll i=1; i<=(ll)(n); ++i)
#define rep3e(i,a,b) for(ll i=(ll)(a); i<=(ll)(b); ++i)
#define rep4e(i,a,b,c) for(ll i=(ll)(a); i<=(ll)(b); i+=(c))
#define repe(...) cut4(__VA_ARGS__,rep4e,rep3e,rep2e,rep1e)(__VA_ARGS__)
#define per1(n) for(ll i=((ll)n)-1; i>=0; --i)
#define per2(i,n) for(ll i=((ll)n)-1; i>=0; --i)
#define per3(i,a,b) for(ll i=((ll)b)-1; i>=(ll)(a); --i)
#define per4(i,a,b,c) for(ll i=((ll)b)-1; i>=(ll)(a); i-=(c))
#define per(...) cut4(__VA_ARGS__,per4,per3,per2,per1)(__VA_ARGS__)
#define per1e(n) for(ll i=((ll)n); i>=1; --i)
#define per2e(i,n) for(ll i=((ll)n); i>=1; --i)
#define per3e(i,a,b) for(ll i=((ll)a); i>=(ll)(b); --i)
#define per4e(i,a,b,c) for(ll i=((ll)a); i>=(ll)(b); i-=(c))
#define pere(...) cut4(__VA_ARGS__,per4e,per3e,per2e,per1e)(__VA_ARGS__)
#define rep_subset(i,s) for(ll i=(s); i>=0; i=(i==0?-1:(i-1)&(s)))
// #define forit(v) for (auto it = v.begin(); it != v.end(); it++)
// #define forit2(it, v) for (auto it = v.begin(); it != v.end(); it++)
// #define forrit(v) for (auto it = v.rbegin(); it != v.rend(); it++)
// #define forrit2(it, v) for (auto it = v.rbegin(); it != v.rend(); it++)

// #ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(vector<vector<T>> x){cerr << "\n"; for(auto i: x) {for(auto j : i) {cerr << j << ' ';} cerr << "\n";}}
template<typename T> void _do(vector<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(unordered_set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(T && x) {cerr << x << endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}
// #else
// #define bug(...) 777771449
// #endif

const ll MOD = 1e9 + 7;
const ll INF = (1ll << 59);

const string FILENAME = "lca";
ifstream fin(FILENAME + ".in");
ofstream fout(FILENAME + ".out");

#define cin fin
#define cout fout

ll log2_[300005];

class SparseTable;
class Graph;
class Lca;

class SparseTable
{
public:

	vec<vec<ll>> st;
	vec<ll> *p;
	
	ll minInd(ll i, ll j);
	void build(vec<ll>& v);
	ll query(ll l, ll r);
};

class Graph
{
public:

	ll n;
	vec<flist<ll>> adj;
	Lca *lcao;
	
	void read();
	ll lca(ll a, ll b);
};

class Lca
{
public:

	vec<ll> etour, level, appear;
	SparseTable *st;
	Graph *g;
	
	void build(Graph *gc);
	ll lca(ll a, ll b);
	void tourDfs(ll u, ll p, ll l);
};

ll Lca::lca(ll a, ll b)
{
	ll ia = appear[a], ib = appear[b];
	if(ia > ib) swap(ia, ib);
	return etour[st->query(ia, ib)];
}
void Lca::tourDfs(ll u, ll p, ll l)
{
	etour.pb(u);
	level.pb(l);
	appear[u] = etour.size() - 1;
	
	for(auto v : g->adj[u])
	{
		if(v == p) continue;
		tourDfs(v, u, l+1);
		
		etour.pb(u);
		level.pb(l);
	}
}
void Lca::build(Graph *gc)
{
	g = gc;
	st = new SparseTable;
	
	etour.reserve(2*g->n+10);
	level.reserve(2*g->n+10);
	appear.resize(g->n);
	
	tourDfs(0, -1, 0);
	st->build(level);
}
ll Graph::lca(ll a, ll b)
{
	return lcao->lca(a, b);
}
void Graph::read()
{
	lcao = new Lca;
	
	ll q;
	cin >> n >> q;
	adj.resize(n);
	rep(n-1)
	{
		ll x;
		cin >> x;
		x--;
		adj[x].pf(i+1);
		adj[i+1].pf(x);
	}
	lcao->build(this);
	
	rep(q)
	{
		ll a, b;
		cin >> a >> b;
		a--, b--;
		cout << lca(a, b)+1 << nl;
	}
}
ll SparseTable::minInd(ll i, ll j)
{
	if(p->at(i) < p->at(j)) return i;
	return j;
}
void SparseTable::build(vec<ll>& v)
{
	p = &v;
	st.ass(log2_[v.size()]+1, vec<ll>(v.size()));
	rep(v.size()) st[0][i] = i;
	rep(k, 1, st.size())
	{
		ll p2 = (1ll<<k);
		for(ll i = 0; i + p2 - 1 < st[0].size(); i++)
		{
			st[k][i] = minInd(st[k-1][i], st[k-1][i+(p2>>1ll)]);
		}
	}
}
ll SparseTable::query(ll l, ll r)
{
	ll k = log2_[r-l+1];
	return minInd(st[k][l], st[k][r-(1ll<<k)+1]);
}

int main()
{
	log2_[1] = 0;
	rep(i, 2, 300005) log2_[i] = log2_[i/2] + 1;
	
	Graph g;
	g.read();
	
    return 0;
}