#include <iostream>
using namespace std;

double geometricSum(double a, double x, int n) {
    double sum = 0.0;
    double power = 1.0 / x; // Start from x^(-1)

    for (int i = 0; i <= n; ++i) {
        sum += a * power;
        power *= x; // Next: x^(i - 1 + 1) = x^i
    }

    return sum;
}

int main() {
    double a, x;
    int n;

    cout << "Enter value of a (initial coefficient): \n";
    cin >> a;
    cout<<a;

    cout << "Enter value of x (base): \n";
    cin >> x;
    cout<<x;

    cout << "Enter value of n (number of terms - 1): \n";
    cin >> n;
    cout<<n;

    double result = geometricSum(a, x, n);
    cout << "Geometric sum S = " << result << endl;

    return 0;
}