#include <iostream>
#include <cmath>

using namespace std;
using usi = unsigned short int;

int main()
{
    unsigned short int      K(0);
    long int                Sum(0);

    cout << "Input K: ";
    cin >> K;
    
    for(usi i = K; i != 0; i--){
        Sum += pow(i, 3.0);
    }
    
    cout << Sum << endl;
    return 0;
}