#include <cstdio>
#include <algorithm>
#include <vector>
#include <cmath>
using namespace std;
#define Max 100001
vector<int>g[Max];
int n,k,w[2*Max],h[2*Max],pos[Max],c[2*Max][19];

void dfs(int x,int r)
{
    int y;
    k++;
    w[k]=x;
    h[k]=r;
    for(int i=0;i<g[x].size();i++)
    {
        y=g[x][i];
        dfs(y,r+1);
        k++;
        w[k]=x;
        h[k]=r;
    }
}

void lca()
{
    for(int i=1;i<=k;i++)
    if(pos[w[i]]==0)pos[w[i]]=i;

//for(int i=1;i<=n;i++)printf("%d ",pos[i]);
    for(int i=1;i<=k;i++)c[i][0]=i;
    for(int j=1;(1<<j)<=k;j++)
    for(int i=1;i+(1<<j)-1<=k;i++)
    if(h[ c[i][j-1] ] < h[ c[i+(1<<(j-1))][j-1] ]) c[i][j]=c[i][j-1]; else c[i][j]=c[i+(1<<(j-1))][j-1];
  //  for(int i=1;i<=30;i++){for(int j=0;j<=10;j++)printf("%d ",w[c[i][j]]);printf("\n");}
}

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);
   /* for(int i=1;i<=k;i++)printf("%d ",w[i]); printf("\n");
    for(int i=1;i<=k;i++)printf("%d ",h[i]); printf("\n");
    printf("%d\n",k); */
    lca();
        while(m--)
        {
            scanf("%d %d",&x,&y);
            x=pos[x];
            y=pos[y];
            if(x>y)swap(x,y);
            k=log(y-x+1)/log(2);
            //printf("%d %d\n",w[c[17][1]],w[c[18][1]]);
            if(h[ c[x][k] ] < h[ c[y-(1<<k)+1][k] ])printf("%d\n",w[c[x][k]]); else printf("%d\n",w[c[y-(1<<k)+1][k]]);
           // printf("%d %d\n",x,y);
        }
    return 0;
}