// infoarena: problema/lca //

#include <fstream>
#include <algorithm>
#include <vector>
#include <cmath>
#define MAXN 100010
#define MAXM 2000010
using namespace std;

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

vector<int> g[MAXN];
int rmq[20][MAXN*10],i,j,n,m,a,b,k,x[MAXN*10],q,first[MAXN];

void dfs(int nod)
{
	x[++q] = nod;
	
	for(int i=0; i<g[nod].size(); ++i)
		dfs(g[nod][i]), x[++q] = nod;
}

int main()
{
	in>>n>>m;
	
	for(i=2; i<=n; i++)
	{
		in>>a;
		g[a].push_back(i);
	}
	
	dfs(1);
	
	for(i=1; i<=q; i++)
		if(!first[x[i]])
			first[x[i]] = i;
		
	for(i=1; i<=q; i++)
		rmq[0][i] = i;
		
	for(j=1; (1<<j) <= q; j++)
		for(i=1; i + (1<<j) <=q+1; i++)
			if(x[rmq[j-1][i]] < x[rmq[j-1][i + (1<<(j-1))]])
				rmq[j][i] = rmq[j-1][i];
			else
				rmq[j][i] = rmq[j-1][i + (1<<(j-1))];
	
	for(i=1; i<=m; i++)
	{
		in>>a>>b;
		
		if(a == b)
		{
			out<<a;
			continue;
		}
		
		a = first[a];
		b = first[b];
		
		if(a > b)
			swap(a,b);
		
		k=1;
		while(1<<(k+1) < b-a+1)
			k++;
		
		out << min(x[rmq[k][a]], x[rmq[k][b - (1<<k) + 1]])<<'\n';
	}
	
	return 0;
}