#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n, k, a[10005], b[10005];
    double m, h;
    cin>>n>>k;
    for(int i=1;i<=n;i++)
    {
        if(i%k==0)
        {
            a[i]=i;
        }
        else
        {
            b[i]=i;
        }
    }
    double sum=0.0, sum1=0.0;
    for(int j=1;j<=n;j++)
    {
        sum+=a[j];
        sum1+=b[j];
        if(j==n)
        {
            sum=sum/j;
            sum1=sum1/j;
        }
    }
    cout<<fixed<<setprecision(1)<<sum<<sum1;
    return 0;
}