#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#define INF 2140000000
#define MaxN 100005
#define MaxLog 18
using namespace std;
       
FILE *IN,*OUT;
int N,M,X,Y,Ans,Log,size=0;
int E[2*MaxN],Lvl[2*MaxN],rmq[MaxLog][2*MaxN],first[MaxN],L[2*MaxN];
vector<int> Graph[MaxN];
void DFS(int node,int level)
{
    first[node]=++size;
    Lvl[size]=level;
    E[size]=node;
    for(int i=0;i<Graph[node].size();i++)
    {
        DFS(Graph[node][i],level+1);
        E[++size]=node;
        Lvl[size]=level;
    }
}
int main()
{
    IN=fopen("lca.in","r");
    OUT=fopen("lca.out","w");
 
    fscanf(IN,"%d%d",&N,&M);
     
    for(int i=2;i<=N;i++)
        fscanf(IN,"%d",&X),Graph[X].push_back(i);
    DFS(1,0);
    for(int i=2;i<=size;i++)
        L[i]=1+L[i/2];
    for(int i=1;i<=size;i++)
        rmq[0][i]=i;
    for(int i=1;i<MaxLog;i++)
        for(int j=1;j<=size;j++)
        {
            rmq[i][j]=rmq[i-1][j];
            if(j>(1<<i-1)&&Lvl[rmq[i][j]]>Lvl[rmq[i-1][j-(1<<i-1)]])
                rmq[i][j]=rmq[i-1][j-(1<<i-1)];
        }
    for(int i=1;i<=M;i++)
    {
        fscanf(IN,"%d%d",&X,&Y);
        X=first[X];
        Y=first[Y];
        if(X>Y)
        {
            int t=X;
            X=Y;
            Y=t;
        }
        Log=L[Y-X+1];
        Ans=rmq[Log][Y];
        if(Lvl[Ans]>Lvl[rmq[Log][X+(1<<Log)-1]])
            Ans=rmq[Log][X+(1<<Log)-1];
        fprintf(OUT,"%d\n",E[Ans]);
    }
    return 0;
}