#include <fstream>

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