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

vector<int>g[MAX];

int n,niv[2*MAX],nod[2*MAX],pos[2*MAX],nr;
int r[2*MAX][20];
bool was[2*MAX];

void dfs(int x,int k){
    nod[nr] = x;
    niv[nr] = k;
    nr++;
    for(int i=0;i<g[x].size();i++)
    {
        dfs(g[x][i],k+1);
        nod[nr] = x;
        niv[nr] = k;
        nr++;
    }
}

void rmq(){
    for(int i=0;i<nr;i++)r[i][0]=i;
    for(int j=1;(1<<j)<=nr;j++)
    for(int i=0;i+(1<<j)<=nr;i++)
    {
        if(niv[ r[i][j-1] ] < niv[ 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];
    }
  /*for(int i=0;i<nr;i++){
        for(int j=0;j<=10;j++)printf("%d ",r[i][j]); printf("\n"); } */
}

int main(){
    int m,x,y;
    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); //tata nodului i este x
        }
    dfs(1,0);

   /* for(int i=0;i<nr;i++)printf("%d ",nod[i]);
    printf("\n");
    for(int i=0;i<nr;i++)printf("%d ",niv[i]); printf("\n"); */

    rmq();
    for(int i=0;i<nr;i++)
    if( !was[ nod[i] ] )
    {
        pos[ nod[i] ] = i;
        was[ nod[i] ] = 1;
    }
   // for(int i=1;i<=n;i++)printf("%d ",pos[i]);
        while(m--)
        {
            scanf("%d %d",&x,&y);
            x = pos[x];
            y = pos[y]; if(x > y) swap(x,y);
            int k = log(y-x+1)/log(2);
       //     printf("%d %d %d ",x,y,k);
            printf("%d\n",min(  nod[ r[x][k] ],nod[ r[y-(1<<k)+1][k] ]));
        }
    return 0;
}