#include<bits/stdc++.h>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
vector<int>v[100001];
int nr,ap[100001];
pair<int,int>rmq[800001][21];
void calculeaza_rmq()
{
	int k=log2(nr);
	for(int j=1;j<=k+1;j++)
		for(int i=1;i<=nr-(1<<j)+1;++i)
		{
		    int x=rmq[i][j-1].first;
		    int y=rmq[i][j-1].second;
		    int x2=rmq[i+(1<<(j-1))][j-1].first;
		    int y2=rmq[i+(1<<(j-1))][j-1].second;
		    if(x<x2)
                rmq[i][j]={x,y};
            else
                rmq[i][j]={x2,y2};
		}
}
void dfs(int nod,int grad)
{
	rmq[++nr][0].first=grad;
	rmq[nr][0].second=nod;
	if(v[nod].size()==0)
	{
		return;
	}
	for(int i=0;i<v[nod].size();i++)
		if(!ap[v[nod][i]])
		{
			ap[v[nod][i]]=nr+1;
			dfs(v[nod][i],grad+1);
			rmq[++nr][0].first=grad;
            rmq[nr][0].second=nod;
		}
}
void citeste()
{
	int n,m;
	f >> n >> m;
	for(int i=2;i<=n;i++)
	{
		int a;
		f>>a;
		v[a].push_back(i);
	}
	ap[1]=1;
	dfs(1,0);
	calculeaza_rmq();
	while(m--)
	{
		int st,dr;
		f>>st>>dr;
		st=ap[st];
		dr=ap[dr];
		if(st>dr)
            swap(st,dr);
		int k=log2(dr-st+1);
		int x=rmq[st][k].first;
		int y=rmq[st][k].second;
		int x2=rmq[dr-(1<<k)+1][k].first;
		int y2=rmq[dr-(1<<k)+1][k].second;
		if(x<x2)
            g<<y<<"\n";
        else g<<y2<<"\n";
	}
}
int main()
{
	citeste();
	calculeaza_rmq();
	return 0;
}