#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

inline int power(int a, int b, int mod=M) {
    int x = 1;
    a %= mod;
    while (b) {
        if (b & 1) x = (x * a) % mod; 
        a = (a * a) % mod;
        b >>= 1;
    }
    return x;
}


//_ ***************************** START Below *******************************




vector<int> a;

int consistency1(int n, int m, int k){
	
	vector<vector<int>> dp(n+1, vector<int>(k+1, -INF));
	dp[0][0] = 0;
	
	for(int i=m; i<=n; i++){
		
		for(int x=1; x<=k; x++){
			
			int sum = 0;
			int j = i;
			while(j>=i-m+1){
				sum += a[j-1];
				j--;
			}
			
			while(j>=0){
				dp[i][x] = max(dp[i][x] , dp[j][x-1] + sum );
				j--;
			}
		}
	}
	
	int maxi = -INF;
	for(int i=1; i<=n; i++){
		maxi = max(maxi, dp[i][k]);
	}
	
	return maxi;
}




int consistency2(int n, int m, int k){
	
	vector<vector<int>> dp(n+1, vector<int>(k+1, -INF));
	vector<vector<int>> pMaxi(n+1, vector<int>(k+1, 0));
	dp[0][0] = 0;
	
	for(int x=1; x<=k; x++){
			
		int sum = 0;
		for(int i=1, j=1; i<=n; i++){
			sum += a[i-1];
	
			if(i-j == m){
				sum -= a[j-1];
				j++;
			}		
			
			if(i-j+1 == m){
				dp[i][x] = pMaxi[j-1][x-1] + sum;
				pMaxi[i][x] = max(pMaxi[i-1][x], dp[i][x]);
			}
		}
	}
	
	
	return pMaxi[n][k];
}




//* Space optimized 

int consistency3(int n, int m, int k){
	
	vector<int> prevPMaxi(n+1, 0);
	vector<int> curPMaxi(n+1, 0);
	
	for(int x=1; x<=k; x++){
			
		int sum = 0;
		for(int i=1, j=1; i<=n; i++){
			sum += a[i-1];
	
			if(i-j == m){
				sum -= a[j-1];
				j++;
			}		
			
			if(i-j+1 == m){
				int dp = prevPMaxi[j-1] + sum;
				curPMaxi[i] = max(curPMaxi[i-1], dp);
			}
		}
		
		prevPMaxi = curPMaxi;
	}
	
	
	return prevPMaxi[n];
}
















int practice(int n, int m, int k){


    return 0;
}





void solve() {
    
    int n, m, k;
    cin>> n >> m >> k;
    
    a.resize(n);
    for(int i=0; i<n; i++) cin >> a[i];
    
    // cout << consistency1(n, m, k) << " " << consistency2(n, m, k) << " " << consistency3(n, m, k) << endl;
    cout << consistency3(n, m, k) << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}