#include <iostream>
#include<bits/stdc++.h>
 
using namespace std;
 
int main() {
	// your code goes here
	int n,k;
	cin>>n>>k;
	vector<int> arr(n);
	for(int i=0;i<n;i++){
		cin>>arr[i];
	}
 
	unordered_map<int,int> mpp;
	int i=0;
	int j=0;
	int sum=0;
	int ans=0;
 
 
	while(j<n){
		mpp[arr[j]]++;
		sum+=arr[j];
 
		if(j-i+1>k){
			mpp[arr[i]]--;
			sum-=arr[i];
			if(mpp[arr[i]]==0){
				mpp.erase(arr[i]);
			}
			i++;
 
		}
		if(mpp.size()==k){
			ans=max(ans,sum);
 
		}
		j++;
	}
	cout<<ans<<endl;
 
	return 0;
}

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NyAzIAoxIDIgNyA3IDQgMyA2

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