#include<iostream>
#include<cstdio>

using namespace std;

int main(){
	int n,k;
	cin>>n>>k;
	int a[10001],b[10001],ta = 0,tb = 0;
	int suma,sumb;
	double avea,aveb;
	for(int i = 1; i <= n;i++)
	{
		if(i%k == 0)
		{
			a[ta] = i;
			ta++;
		}
		else
		{
			b[tb] = i;
			tb++;
		}
	}
	for(int i = 0;i < ta; i++)
	{
		suma+=a[i];
	}
	for(int i = 0;i < tb; i++)
	{
		sumb+=b[i];
	}
	avea = suma / ta;
	aveb = sumb / tb;
	printf("%.1lf, %.1lf", suma / (double)ta, sumb / (double)tb);
	return 0;
}

求助各位大佬，为何跑样例时第二个数据结果为50.2QAQ