#include <iostream>
#include <iomanip>
using namespace std;
float  e, c;

int main() {

	int  n, k, sum1 = 0, sum2 = 0;
	cin >> n >> k;
	for (int i = 1; i <= n; i++) {
		if (i % k == 0) {
			e += i;
			sum1++;
		} else {
			c += i;
			sum2++;
		}
		cout << e << "     " << c << endl << endl;
	}
	e /= sum1 * 1.0;
	c /= sum2 * 1.0;

	printf("%.1f\n", e);
	printf("%.1f\n", c);
	return 0;
}