#include<fstream.h>
int n,m,eu[200000],niv[200000],ver[100000],leg[100000],padre[100000],rmq[18][200000],lg[200000],beg[100000];
void dfs(int nod, int nivel)
{
	eu[++eu[0]]=nod;
	niv[eu[0]]=nivel;
	if(!beg[nod])
		beg[nod]=eu[0];
	int t=lg[nod];
	while(t)
	{
		dfs(ver[t],nivel+1);
		t=leg[t];
	}
	if(padre[nod])
	{
		eu[++eu[0]]=padre[nod];
		niv[eu[0]]=nivel-1;
	}
}
int main()
{
	int x,i,y,j,l;
	ifstream f("lga.in");
	ofstream g("lga.out");
	f>>n>>m;
	for(i=2;i<=n;i++)
	{
		f>>x;
		padre[i]=x;
		ver[i-1]=i;
		leg[i-1]=lg[x];
		lg[x]=i-1;
	}
	dfs(1,0);
	lg[1]=0;
	for(i=2;i<=eu[0];i++)
		lg[i]=lg[i>>1]+1;
	for(i=1;i<=eu[0];i++)
		rmq[0][i]=i;
	for(j=1;j<=lg[eu[0]];j++)
		for(i=1;j<=lg[eu[0]+1-i];i++)
			if(niv[rmq[j-1][i]]<niv[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))];
	while(m--)
	{
		f>>x>>y;
		x=beg[x];
		y=beg[y];
		if(x>y)
		{
			n=x;
			x=y;
			y=n;
		}
		l=lg[y-x+1];
		if(niv[rmq[l][x]]<niv[rmq[l][y-(1<<l)+1]])
			g<<eu[rmq[l][x]]<<'\n';
		else
			g<<eu[rmq[l][y-(1<<l)+1]]<<'\n';
	}
	return 0;
}