#include <bits/stdc++.h>

using namespace std;
int n,m,tata[100003],euler[250003],kontor,indexx[100003],indi[100003],poz[100003],l[100003],rmq[25][250003];vector <int> arb[1003];
void dfs (int nod) {
	indexx[nod]=++kontor;euler[++euler[0]]=indexx[nod];indi[indexx[nod]]=nod;poz[indexx[nod]]=euler[0];
	for(int i=0;i<(int)arb[nod].size();++i)
		if(indexx[arb[nod][i]]==0) {
			dfs(arb[nod][i]);
			euler[++euler[0]]=indexx[nod];
		}
}
void build_rmq () {
	for(int i=2;i<=euler[0];++i)
		l[i]=l[(i>>1)]+1;
	for(int k=1;k<=euler[0];++k)
		rmq[0][k]=euler[k];
	for(int k=1;k<=l[euler[0]];++k)
		for(int i=1;i+(1<<k)-1<=euler[0];++i)
			rmq[k][i]=min(rmq[k-1][i],rmq[k-1][i+(1<<(k-1))]);
}
int querrys (int p1, int p2) {
	return min(rmq[l[(p2-p1+1)]][p1],rmq[l[p2-p1+1]][p2-(1<<l[p2-p1+1])+1]);
}
int main () {
	int nr,nr1,nr2,ans;
	freopen("lca.in","r",stdin);
	freopen("lca.out","w",stdout);
	scanf("%d%d", &n, &m);++m;
	for(int i=2;i<=n;++i) 
		scanf("%d", &nr),tata[i]=nr,arb[nr].push_back(i),arb[i].push_back(nr);
	dfs(1);build_rmq();
	while(--m) {
		scanf("%d%d", &nr1, &nr2);
		nr1=indexx[nr1];nr2=indexx[nr2];
		ans=querrys(min(poz[nr1],poz[nr2]),max(poz[nr1],poz[nr2]));
		printf("%d\n", indi[ans]);
	}
	return 0;
}