#include <fstream>

using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
#define nmax 100010
struct nod
{
    int val;
    nod *urm;
};
typedef nod *pnod;
pnod p,v[nmax];
int q;
int rmq[19][2*nmax];
int lg[2*nmax],lev[2*nmax],h[2*nmax],first[nmax];
void ad(int x,int y)
{
    p=new nod;
    p->val=y;
    p->urm=v[x]->urm;
    v[x]->urm=p;
}
void euler(int rad,int low)
{
    pnod p;
    p=v[rad]->urm;
    q+=1;
    h[q]=rad;
    first[rad]=q;
    lev[q]=low;
    while(p)
    {
        euler(p->val,low+1);
        q+=1;
        h[q]=rad;
        lev[q]=low;
        p=p->urm;
    }
}
void range()
{
    lg[1]=0;
    int o,i;
    rmq[0][1]=1;
    for(i=2;i<=q;i++)
    {
        lg[i]=lg[i>>1]+1;
        rmq[0][i]=i;
    }
    for(int i=1;(1<<i)<q;i++)
    {
        for(int j=1;j+(1<<i)<=q;j++)
        {
            o=(1<<(i-1));
            if(lev[rmq[i-1][j]]<lev[rmq[i-1][j+o]])
                rmq[i][j]=rmq[i-1][j];
            else
                rmq[i][j]=rmq[i-1][j+o];
        }
    }
}
int minim,dif,l,a,b;
int lca(int x,int y)
{
    x=first[x];
    y=first[y];
    if(x>y)
        swap(x,y);
    dif=y-x+1;
    l=lg[dif];
    minim=rmq[l][x];
    if(lev[minim]>lev[rmq[l][x+dif-(1<<l)]])
        minim=rmq[l][dif-(1<<l)];
    return h[minim];
}
int main()
{
    int n,m,i,x,y,j;
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        v[i]=new nod;
        v[i]->urm=0;
    }
    for(i=2;i<=n;i++)
    {
        f>>x;
        ad(x,i);
      //  ad(i,x);
    }
    euler(1,0);
    range();
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        g<<lca(x,y)<<'\n';
    }
    return 0;
}