#include <fstream>
#include <vector>
#include <bitset>
#define Nmax 100099
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");

int N,M,E[2*Nmax],L[Nmax],First[Nmax],lg[2*Nmax],RMQ[25][Nmax];
vector < int > G[Nmax];
bitset < Nmax > viz;

void ReadInput()
{
     f>>N>>M;
     for(int i=2;i<=N;++i)
     {
          int x;
          f>>x;
          G[x].push_back(i);
     }
}

void DFS(int node,int level)
{
     viz[node]=1;
     E[++E[0]]=node;
     L[node]=level;
     First[node]=E[0];
     for(vector<int>::iterator it=G[node].begin();it!=G[node].end();++it)
          if(!viz[*it])
          {
               DFS(*it,level+1);
               E[++E[0]]=node;
               //L[E[0]]=level;
          }
}

int main()
{
     ReadInput();
     DFS(1,1);
     for(int i=2;i<=E[0];++i)lg[i]=lg[i/2]+1;
     for(int j=1;j<=E[0];++j)RMQ[0][j]=E[j];

     for(int i=1;(1<<i)<=E[0];++i)
          for(int j=1;j<=E[0]-(1<<i)+1;++j)
          {
               int x=RMQ[i-1][j],y=RMQ[i-1][j+(1<<(i-1))];
               if(L[x]<L[y])RMQ[i][j]=x;
                    else RMQ[i][j]=y;
          }
     for(int i=1;i<=M;++i)
     {
          int x,y;
          f>>x>>y;
          int st=First[x],dr=First[y];
          if(st>dr)swap(st,dr);
          int diff=dr-st+1;
          int log=lg[diff];
          int x1=RMQ[log][st],x2=RMQ[log][dr-(1<<log)+1];
          if(L[x1]<L[x2])g<<x1<<'\n';
               else g<<x2<<'\n';
     }
     f.close();g.close();
     return 0;
}