#include <stdio.h>
int main(){
    int n,k;
    float sum;
    scanf("%d%d",&n,&k);
    for(int i=1;i<n;i++)
        if(i%k==0)
        sum+=i;
        printf("%.1f",sum/(n/k));
	    sum = (1 + n) * n / 2 - sum;
	    printf (" %.1f\n", sum / (n - n / k));
	return 0;
    
}