#include <stdio.h>
int main(){
	int n,k;
	scanf("%d %d",&n,&k);
	int c = n/k;
	long int ttl = n*(n+1)/2;
	double s1 = k*(c+1)/2;
	double s2 = (ttl-c*s1)/(n-c);
	printf("%.1f %.1f",s1,s2);	
}

double s1 = k*(c+1)/2; 这一行，如果改为
double s1 = (c+1)/2*k; 则错误。为啥？