哪位大佬能帮我看一下！！！必定关注！

#include<bits/stdc++.h>
#define ll long long
#define inf  0x3f3f3f3f
#define rep(i,x,y) for(i=x; i<=y; i++)
using namespace std;
const ll N=1e7+10;
double s=0,ma=INT_MIN,l=0,s1=0,r=0;
ll n,m;
signed main(void)
{
	cin>>n>>m;
	for(ll i=1; i<=n; i++)
	{
		if(i%m==0?s+=i,l++:s1+=i,r++);

	}
	printf("%.1lf %.1lf",(s/l),(s1/r));
	
	
	return 0;
}