#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
const int nMax=100004;
typedef pair <int,int> p;
int n,m,i,j,x,y,st,dr,L,Nn;
p sol,sol2;
vector <int> graph[nMax];
vector <p> a(1);
int lg[nMax+nMax],rmq[19][nMax+nMax],fPoz[nMax];
void dfs(int nod,int gr)
{
	a.push_back(p(nod,gr));
	if(graph[nod].empty())
	{
		return;
	}
	else
	{
		for(vector <int> ::iterator it=graph[nod].begin();it!=graph[nod].end();it++)
		{
			dfs(*it,gr+1);
			a.push_back(p(nod,gr));
		}
	}
}
int main()
{
	freopen("lca.in","r",stdin);
	freopen("lca.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(i=2;i<=n;i++)
	{
		scanf("%d",&x);
		graph[x].push_back(i);
	}
	dfs(1,0);
	int N=(int)a.size()-1;
	for(i=N;i;i--)
	{
		fPoz[a[i].first]=i;
		rmq[0][i]=i;
	}
	for(i=2;i<=N;i++)
	{
		lg[i]=lg[(i>>1)]+1;
	}
	for(j=1;(1<<j)<N;j++)
	{
		L=1<<(j-1);
		Nn=N-(1<<j)+1;
		for(i=1;i<=Nn;i++)
		{
			rmq[j][i]=rmq[j-1][i];
			if(a[rmq[j-1][i+L]].second<a[rmq[j][i]].second)
				rmq[j][i]=rmq[j-1][i+L];
		}
	}
	for(;m--;)
	{
		scanf("%d%d",&x,&y);
		st=fPoz[x];
		dr=fPoz[y];
		if(st>dr)
			swap(st,dr);
		sol=a[rmq[lg[dr-st+1]][st]];
		sol2=a[rmq[lg[dr-st+1]][dr-(1<<lg[dr-st+1])+1]];
		if(sol2.second<sol.second)
			sol=sol2;
		printf("%d\n",sol.first);
	}
	return 0;
}