救命，题目P6568

#include<iostream>
#include<algorithm>
using namespace std;
const int N=1000010;
int cmp(int a,int b){
	return a>b;
}
int main(){
	int n,k,a[N],b[N];
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int i=1;i<=n-k;i++){
		for(int j=i;j<=i+k;j++){
			b[i]+=a[j];
		}
	}
	sort(b+1,b+n+1,cmp);
	cout<<b[1];
	return 0;
}