#include <fstream>

using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
#define nmax 100100
struct nod
{
    int val;
    nod *urm;
};
typedef nod *pnod;
pnod p,v[nmax];
int val[nmax];
void ad(int x,int y)
{
    p=new nod;
    p->val=y;
    p->urm=v[x]->urm;
    v[x]->urm=p;
}
int lg[2*nmax],lev[2*nmax],first[nmax],a[2*nmax],s,n,m,rmq[19][nmax];
void dfs(int x,int niv)
{
    s+=1;
    first[x]=s;
    a[s]=x;
    lev[s]=niv;
    pnod p=v[x]->urm;
    while(p)
    {
        dfs(p->val,niv+1);
        s+=1;
        a[s]=x;
        lev[s]=niv;
        p=p->urm;
    }
}
void calc_log()
{
    int i;
    for(i=2;i<=s;i++)
    {
        lg[i]=lg[i>>1]+1;
        rmq[0][i]=i;
    }
    rmq[0][1]=1;
}
void calc_rmq()
{
    int i,j,o;
    for(i=1;(1<<i)<s;i++)
    {
        for(j=1;j+(1<<i)<=s;j++)
        {
            o=1<<(i-1);
            if(lev[rmq[i-1][j]]>lev[rmq[i-1][j+o]])
                rmq[i][j]=rmq[i-1][j+o];
            else
                rmq[i][j]=rmq[i-1][j];
        }
    }
}
int cx,cy,act,dif,maxim,part1,part2;
void lca(int x,int y)
{
    cx=x;
    cy=y;
    if(first[cx]>first[y])
        swap(cx,cy);
    dif=first[cy]-first[cx];
    if(lev[rmq[lg[dif]][first[cx]]]>lev[rmq[lg[dif]][first[cy]-(1<<lg[dif])+1]])
        act=rmq[lg[dif]][first[cy]-(1<<lg[dif])+1];
    else
        act=rmq[lg[dif]][first[cx]];
    g<<a[act]<<'\n';
  /*  if(val[a[act]]>maxim)
    {
        maxim=val[a[act]];
        part1=x;
        part2=y;
    }
    else
        if(val[a[act]]==maxim)
    {
        if(part1>x)
        {
            part1=x;
            part2=y;
        }
        else
            if(part1==x and part2>y)
                part2=y;
    }*/
}
int main()
{
    int i,x,y;
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
      //  f>>val[i];
        v[i]=new nod;
        v[i]->urm=0;
    }
    for(i=2;i<=n;i++)
    {
        f>>y;
        x=i;
        ad(y,x);
    }
    dfs(1,0);
    calc_log();
    calc_rmq();
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        lca(x,y);
    }
  //  g<<maxim<<" "<<part1<<" "<<part2;
    return 0;
}