/*Lowest common ancesor*/
#include<cstdio>
#include<list>
#include<algorithm>
using namespace std;

list<int> L[100001];
int n,m,t,level[100001],size_eul,i,j,k,dif,rez;
int RMQ[20][600001], log[200001], first[100001];

int minimum(int a, int b)
{if(level[a]<level[b])
  return a;
return b;}

int maximum(int a, int b)
{if(level[a]>level[b])
  return a;
return b;}

void parcurgere(int x, int lvl)
{first[x]=size_eul+1;
list<int>::iterator it;
for(it=L[x].begin(); it!=L[x].end(); it++)
{size_eul++;
 RMQ[0][size_eul]=x;    //eulerian representation
 parcurgere(*it,lvl+1);}

size_eul++;
RMQ[0][size_eul]=x;  
}

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",&t);
   level[i]=level[t]+1;
   L[t].push_back(i);}
parcurgere(1,1);   

for(i=2; i<=size_eul; i++)
  log[i]=log[i/2]+1;
  

i=1;  
while((1<<i)<=size_eul)
{
for(j=1; j<=(size_eul-(1<<i)+1); j++)
 RMQ[i][j]=minimum(RMQ[i-1][j], RMQ[i-1][j+(1<<(i-1))]);
i++; 
}  

int x,y,pozx,pozy;

for(i=1; i<=m; i++)
{scanf("%d %d",&x,&y);
pozx=first[x];
pozy=first[y];
dif=max(pozx,pozy)-min(pozx,pozy);
k=log[dif+1];
rez=minimum(RMQ[k][min(pozx,pozy)],RMQ[k][max(pozx,pozy)-(1<<k)+1]);
printf("%d\n",rez);  
       
}
   
return 0;}