30分 1,2,3,4,5,7,9WA

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 10010;
int a[N], i, j, n, m;
int mi = INT_MAX;
int sum;
signed main(){
	cin>>n>>m;
	for(i = 1;i <= n;i++){
		cin>>a[i];
	}
	for(i = 1;i <= n - m + 1;i++){
		for(j = i;j <= i + m;j++){
			sum += a[j];
		}
		mi = min(mi, sum);
		sum = 0;
	}
	cout<<mi;
	return 0;
}