// Include
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;

// Definitii
#define pb push_back

#define leftSon (node<<1)
#define rightSon (node<<1)+1

// Constante
const int sz = (int)1e5+1;
const int oo = (1<<30)-1;

// Functii
void dfs(int node);
void treeInsert(int node, int left, int right);
void treeQuery(int node, int left, int right);

// Variabile
ifstream in("lca.in");
ofstream out("lca.out");

int nodes, questions;
int father[sz];
vector<int> euler;
vector<int> graph[sz];

int pos[sz];

int treeVal, treePos;
int leftRange, rightRange;
int tree[sz<<2];

// Main
int main()
{
	in >> nodes >> questions;
	for(int i=2 ; i<=nodes ; ++i)
	{
		in >> father[i];
		graph[father[i]].pb(i);
	}
	dfs(1);
	
	int limit = euler.size();
	for(treePos=1 ; treePos<=limit ; ++treePos)
	{
		treeVal = euler[treePos-1];
		treeInsert(1, 1, limit);
	}
	
	vector<int>::iterator beg = euler.begin();
	while(questions--)
	{
		int node1, node2;
		
		in >> node1 >> node2;
		if(pos[node2] < pos[node1])
			swap(node1, node2);
		
		leftRange = pos[node1];
		rightRange = pos[node2];
		treeVal = oo;
		treeQuery(1, 1, limit);
		out << treeVal << '\n';
	}
	
	in.close();
	out.close();
	return 0;
}

void dfs(int node)
{
	euler.pb(node);
	pos[node] = euler.size() - 1;
	
	vector<int>::iterator it, end=graph[node].end();
	for(it=graph[node].begin() ; it!=end ; ++it)
	{
		dfs(*it);
		euler.pb(node);
	}
}


void treeInsert(int node, int left, int right)
{
	if(left == right)
	{
		tree[node] = treeVal;
		return;
	}
	int mid = (left+right)>>1;
	if(treePos <= mid)
		treeInsert(leftSon, left, mid);
	else
		treeInsert(rightSon, mid+1, right);
	
	tree[node] = min(tree[leftSon], tree[rightSon]);
}

void treeQuery(int node, int left, int right)
{
	if(leftRange <= left && right <= rightRange)
	{
		treeVal = min(treeVal, tree[node]);
		return;
	}
	
	int mid = (left+right)>>1;
	
	if(leftRange <= mid)
		treeQuery(leftSon, left, mid);
	
	if(mid < rightRange)
		treeQuery(rightSon, mid+1, right);
}