#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,k,a[10005],q=0;
	double ping1=0,quan;
	scanf("%d%d",&n,&k);
	for(int i=1;i<n;i++){
		if(i%k==0){
		//	a[q]=i;
			q++;
			ping1=ping1+i;
		}
	}
//	cout<<ping1<<" ";
	double ans1=ping1/q;
	printf("%.1f ",ans1);
	for(int i=1;i<=n;i++){
		quan=quan+i;
	}
	double ans2=(quan-ping1)/(n-q);
	printf("%.1f",ans2);
}