#include<iostream>
#include<cstdio>
using namespace std;
int n,k,cnt1=0,cnt2=0;
double ans1,ans2,sum1,sum2;
int main(){
    cin>>n;
    cin>>k;
	for(int i=1;i<=n;i++){
		if(i%k==0){
			sum1+=i;
			cnt1++;
		}else{
			sum2+=i;
			cnt2++;
		}
	}
	ans1=sum1/cnt1;
	ans2=sum2/cnt2;
	printf("%.1lf,%.1lf",ans1,ans2);
	return 0;
}