#include<stdio.h>
#include<vector>
using namespace std;
vector <int> g[100005];
int elr[200005],nvl[200005],i,n,k=1,x,m,pp[100005],a[20][200005],lg[200005],j,y,ll,aux;
#define minn(a,b) (nvl[a]<nvl[b]) ? a : b

void dfs(int lvl, int nod)
{
	elr[++k]=nod;
	nvl[k]=lvl;
	pp[nod]=k;
	int N=g[nod].size();
	for(int i=0;i<N;++i)
	{
		dfs(lvl+1,g[nod][i]);
		elr[++k]=nod;
		nvl[k]=lvl;
	}
}


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);
		g[x].push_back(i);
	}
	dfs(0,1);
	a[0][1]=1;
	for(i=2;i<=k;++i)
	{
		a[0][i]=i;
		lg[i]=lg[i>>1]+1;
	}
	for(i=1;(1<<i)<=k;++i)
		for(j=1;(1<<i)+j-1<=k;++j)
			a[i][j]=minn(a[i-1][j],a[i-1][(1<<(i-1))+j]);
	for(i=0;i<m;++i)
	{
		scanf("%d%d",&x,&y);
		x=pp[x];
		y=pp[y];
		if(x>y)
		{
			int aux=x;
			x=y;
			y=aux;
		}
		ll=lg[y-x+1];
		printf("%d\n",elr[minn(a[ll][x],a[ll][y-(1<<ll)+1])]);
	}
	return 0;
}