w_i_s_p

#include <fstream>
#define ULL unsigned long long
using namespace std;

void suma(ULL n,ULL s,ULL pas,ULL &sol) /// Calculez suma recursiv
{
    if(s<n*n-4)
        s+=pas,sol+=s,s+=pas,sol+=s,suma(n,s,pas-4,sol);
}

int main()
{
    ifstream f("wisp.in");
    ULL n,k;
    f>>n>>k;
    f.close();
    ULL s=1,sol=0,pas=2*(n-1); /// pas=pasul initial
    sol=n*(k-1)+1; /// Corectez valorea pentru k;
    suma(n,s,pas,sol);
    if(n%2==0) /// Pentru n par
        sol+=n*n-1; /// iau in calcul si ultima valoare
    ofstream g("wisp.out");
    g<<sol;
    g.close();
    return 0;
}