#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

int maxi;

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

ifstream f("test.in");

void creare(nod *&prim, nod *&ultim)
{
    int n,i;
    nod *nou;
    f>>n;
    prim= new nod;
    f>>prim->nr;
    prim->urm=NULL;
    ultim=prim;

    for(i=2; i<=n; i++)
    {
        nou=new nod;
        f>>nou->nr;
        nou->urm=NULL;
        ultim->urm=nou;
        ultim=nou;
    }
}

void afisare(nod *prim)
{
    nod *a;

    for(a=prim; a!=NULL; a=a->urm)
        cout<<a->nr<<" ";
}

void eliminare(nod *&prim)
{
    nod *aux;
    aux=prim;
    prim=prim->urm;
    delete aux;
}

void adaugare(nod *&ultim)
{
    nod *nou;
    nou=new nod;
    cin>>nou->nr;
    nou->urm=NULL;
    ultim->urm=nou;
    ultim=nou;
}

int patrat(int n)
{
    int sq=sqrt(n);
    if(sq*sq==n)return 1;
    return 0;
}

void mapatrate(nod *prim)
{
    nod *a;
    int s=0,c=0;

    for(a=prim; a!=NULL; a=a->urm)
        if(patrat(a->nr)==1)
        {
            c++;
            s=s+a->nr;
        }
    cout<<(float)s/c;
}

void maxim(int &n, nod *prim)
{
    nod *a;
    for(a=prim; a!=NULL; a=a->urm)
        if(a->nr>n)n=a->nr;
}

void vecini(nod *prim)
{
    nod *a;
    a=prim;
    while(a->urm!=NULL)
    {
        if(a->nr==maxi)
            cout<<a->urm->nr<<" ";
        if(a->urm->nr==maxi)
            cout<<a->nr<<" ";
        a=a->urm;
    }
}

int main()
{
    nod *prim,*ultim;

    creare(prim,ultim);
    cout<<endl<<"coada: ";
    afisare(prim);
    cout<<endl<<endl;

    cout<<"Adaug ";
    adaugare(ultim);
    cout<<endl<<"coada: ";
    afisare(prim);
    cout<<endl<<endl;

    cout<<"sterg un element";
    eliminare(prim);
    cout<<endl<<endl<<"coada: ";
    afisare(prim);
    cout<<endl<<endl;

    cout<<"med arit a nr patrate este ";
    mapatrate(prim);
    cout<<endl<<endl;

    maxi=prim->nr;
    maxim(maxi,prim);
    cout<<"maximul este "<<maxi<<" si are vecinii ";
    vecini(prim);
    cout<<endl;
}