#include <cstdio>
#include <cstring>
#define Nmx 100001
#define INF 0x3f3f3f3f

using namespace std;

struct nod{int inf;nod *urm;};

nod *G[Nmx];
int n,m,AA,B,nr,First[Nmx],L[Nmx<<1],H[Nmx<<1],A[Nmx*8];
int sol,hsol;

void add(int x,int y)
{
    nod *aux=new nod;
    aux->inf = y;
    aux->urm = G[x];
    G[x]=aux;
}

void read()
{
    int x;
    scanf("%d%d",&n,&m);
    for(int i=2;i<=n;++i)
    {
        scanf("%d",&x);
        add(x,i);
    }
}

void dfs(int nd,int niv)
{
    L[++nr]=niv;
    H[nr]=nd;
    First[nd]=nr;
    for(nod *p=G[nd];p;p=p->urm)
    {
        dfs(p->inf,niv+1);
        L[++nr]=niv;
        H[nr]=nd;
    }
}

void build(int nd,int st,int dr)
{
    if(st==dr)
    {
        A[nd]=st;
        return;
    }
    int mij=(st+dr)/2;
    build(nd*2,st,mij);
    build(nd*2+1,mij+1,dr);
    if(L[A[nd*2]]<L[A[nd*2+1]])
        A[nd]=A[nd*2];
    else A[nd]=A[nd*2+1];
}

void query(int nd,int st,int dr)
{
    if(st>=AA&&dr<=B)
    {
        if(L[A[nd]]<sol)
        {
            sol=L[A[nd]];
            hsol=H[A[nd]];
        }
        return;
    }
    int mij=(st+dr)/2;
    if(AA<=mij) query(nd*2,st,mij);
    if(B>mij) query(nd*2+1,mij+1,dr);
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    read();
    dfs(1,0);
    build(1,1,nr);
    int x,y;
    for(;m;m--)
    {
        scanf("%d%d",&x,&y);
        AA=First[x];B=First[y];
        if(AA>B) AA^=B^=AA^=B;
        sol=hsol=INF;
        query(1,1,nr);
        printf("%d\n",hsol);
    }
    return 0;
}