#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#define INF 2140000000
#define MaxN 100005
#define MaxLog 18
using namespace std;
      
FILE *IN,*OUT;
int N,M,X,Y,Ans,Log,size=0;
int E[2*MaxN],Lvl[2*MaxN],rmq[MaxLog][2*MaxN],first[MaxN],L[2*MaxN];
vector<int> Graph[MaxN];
void DFS(int node,int level)
{
	first[node]=++size;
	Lvl[size]=level;
	E[size]=node;
	for(int i=0;i<Graph[node].size();i++)
	{
		DFS(Graph[node][i],level+1);
		E[++size]=node;
		Lvl[size]=level;
	}
}
int main()
{
    IN=fopen("lca.in","r");
    OUT=fopen("lca.out","w");

	fscanf(IN,"%d%d",&N,&M);
	
	for(int i=2;i<=N;i++)
		fscanf(IN,"%d",&X),Graph[X].push_back(i);
    DFS(1,0);
	for(int i=2;i<=size;i++)
		L[i]=1+L[i/2];
	for(int i=1;i<=size;i++)
		rmq[0][i]=i;
	for(int i=1;i<MaxLog;i++)
		for(int j=1;j<=size;j++)
		{
			rmq[i][j]=rmq[i-1][j];
			if(j>(1<<i-1)&&Lvl[rmq[i][j]]>Lvl[rmq[i-1][j-(1<<i-1)]])
				rmq[i][j]=rmq[i-1][j-(1<<i-1)];
		}
	for(int i=1;i<=M;i++)
	{
		fscanf(IN,"%d%d",&X,&Y);
		X=first[X];
		Y=first[Y];
		if(X>Y)
		{
			int t=X;
			X=Y;
			Y=t;
		}
		Log=L[Y-X+1];
		Ans=rmq[Log][Y];
		if(Lvl[Ans]>Lvl[rmq[Log][X+(1<<Log)-1]])
			Ans=rmq[Log][X+(1<<Log)-1];
		fprintf(OUT,"%d\n",E[Ans]);
	}
	return 0;
}