cpp

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int n,a[N],s[N],k,minn=999999;
int main(){
    cin>>n>>k;
    for(int i=1;i<=n;i++){
    	cin>>a[i];
    	s[i]=s[i-1]+a[i];
	}
	for(int i=1;i<=n-(k-1);i++){
		int ans=s[i+(k-1)]-s[i-1];
		minn=min(minn,ans);
	}
	cout<<minn;
	return 0;
}