#include <iostream>
using namespace std;
int main(){
double sum=0,x,jomleghabl;
int n;
cout << "Please Enter x & n (Separate With Space) \n";
cin >> x >> n;
jomleghabl = -((x*x*x)/6);
sum=x+jomleghabl;
for (int i =3; i <= n ;i++){
jomleghabl *= -((x*x)/(i+1));
sum += jomleghabl ;
}
cout << "sum is : " << sum;
return 0;
}