#include <iostream>
using namespace std;

int jumlahDeret (int n) {
	if (n == 1)
	return 1;
	return n + jumlahDeret (n-1);
}

int main () {
	int n = 7;
	cout << "Jumlah 1 sampai " << n << " = " << jumlahDeret (n) << endl;
	return 0;
}