#include<cstdio>
#include<vector>
using namespace std;
int N,M;
vector<int> nr[100010];
int rmq[18][200010],lg[200010],papar[100010];
int neu[200010],heu[200010],euler;
char viz[200010];
inline int minim(int a,int b){
  if(heu[a]<heu[b])
    return a;
  return b;
}
void df(int x,int H){
  viz[x]=1;
  heu[++euler]=H;
  neu[euler]=x;
  papar[x]=euler;
  for(vector<int>::iterator it=nr[x].begin();it!=nr[x].end();++it){
    if(!viz[*it]){
      df(*it,H+1);
      heu[++euler]=H;
      neu[euler]=x;
    }
  }
}
int main(){
  freopen("lca.in","r",stdin);
  freopen("lca.out","w",stdout);
  int i,j,x,y,L;
  scanf("%d%d",&N,&M);
  for(i=2;i<=N;++i){
    scanf("%d",&x);
    nr[x].push_back(i);
    lg[i]=lg[i>>1]+1;
  }
  df(1,0);
  for(i=1;i<=euler;++i){
    rmq[0][i]=i;
  }
  for(i=1;(1<<i)<=(N<<1)-1;++i){
    for(j=1;j<=(N<<1)-(1<<i);++j){
      rmq[i][j]=minim(rmq[i-1][j],rmq[i-1][j+(1<<(i-1))]);
    }
  }
  for(i=0;i<M;++i){
    scanf("%d%d",&x,&y);
    x=papar[x];
    y=papar[y];
    if(y<x){
      j=x;
      x=y;
      y=j;
    }
    L=lg[y-x+1];
    L=minim(rmq[L][x],rmq[L][y+1-(1<<L)]);
    printf("%d\n",neu[L]);
  }
  fclose(stdin);
  fclose(stdout);
  return 0;
}