HV C++

#include <bits/stdc++.h>
using namespace std;
int a,p,s;
int main ()
{
    freopen ("hv.inp","r",stdin);
    freopen ("hv.out","w",stdout);
    cin>>a;
    p=a*4;
    s=a*a;
    cout<<"Chu vi la: "<<p<<endl;
    cout<<"Dien tich la: "<<s;
}