#include <cstdio>
#include <algorithm>
#include <vector>
#include <cmath>
using namespace std;
#define MAX 100001

vector<int>g[MAX];

int n,h[2*MAX],c[2*MAX],l,r[2*MAX][20],pos[MAX];

void dfs(int x,int niv){
    h[l]=niv; //setam nivelul nodului
    c[l]=x;   //setam nodul
    l++;
    for(int i=0;i<g[x].size();i++)
    {
        dfs(g[x][i],niv+1);
        h[l]=niv; //setam nivelul nodului
        c[l]=x;   //setam nodul
        l++;
    }
}

void rmq(){
    for(int i=0;i<l;i++)r[i][0]=i;
    for(int j=1;(1<<j)<=l;j++)
    for(int i=0;i+(1<<j)<=l;i++)
    if(h[r[i][j-1]]<h[r[i+(1<<(j-1))][j-1]])r[i][j]=r[i][j-1]; else r[i][j]=r[i+(1<<(j-1))][j-1];
}

int main(){
    int m,x,y,k;
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
        scanf("%d %d",&n,&m);
        for(int i=2;i<=n;i++)
        {
            scanf("%d",&x);
            g[x].push_back(i);
        }
    dfs(1,0); // parcurgere euler
    rmq();

    for(int i=0;i<l;i++)
    if(pos[c[i]]==0)pos[c[i]]=i;

       while(m--)
        {
            scanf("%d %d",&x,&y);
            x=pos[x]; y=pos[y]; if(x>y)swap(x,y);
            k=(long double)log(y-x+1)/(long double)log(2);
            if(h[r[x][k]]<h[r[y-(1<<k)+1][k]])k=r[x][k]; else k=r[y-(1<<k)+1][k];
            printf("%d\n",c[k]);
        }

  //  for(int i=0;i<l;i++){
  //   for(int j=0;j<=10;j++)printf("%d ",r[i][j]); printf("\n"); }

    //for(int i=1;i<=l;i++)printf("%d ",c[i]); printf("\n");
    //for(int i=1;i<=l;i++)printf("%d ",h[i]); printf("\n");
    return 0;
}