#####segfunc#####
def segfunc(x, y):
    return max(x,y)
#################

#####ide_ele#####
ide_ele = -10**18
#################

class SegTree:
    """
    init(init_val, ide_ele): 配列init_valで初期化 O(N)
    update(k, x): k番目の値をxに更新 O(logN)
    query(l, r): 区間[l, r)をsegfuncしたものを返す O(logN)
    """
    def __init__(self, init_val, segfunc, ide_ele):
        """
        init_val: 配列の初期値
        segfunc: 区間にしたい操作
        ide_ele: 単位元
        n: 要素数
        num: n以上の最小の2のべき乗
        tree: セグメント木(1-index)
        """
        n = len(init_val)
        self.segfunc = segfunc
        self.ide_ele = ide_ele
        self.num = 1 << (n - 1).bit_length()
        self.tree = [ide_ele] * 2 * self.num
        # 配列の値を葉にセット
        for i in range(n):
            self.tree[self.num + i] = init_val[i]
        # 構築していく
        for i in range(self.num - 1, 0, -1):
            self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])

    def update(self, k, x):
        """
        k番目の値をxに更新
        k: index(0-index)
        x: update value
        """
        k += self.num
        self.tree[k] = x
        while k > 1:
            self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
            k >>= 1

    def query(self, l, r):
        """
        [l, r)のsegfuncしたものを得る
        l: index(0-index)
        r: index(0-index)
        """
        res = self.ide_ele

        l += self.num
        r += self.num
        while l < r:
            if l & 1:
                res = self.segfunc(res, self.tree[l])
                l += 1
            if r & 1:
                res = self.segfunc(res, self.tree[r - 1])
            l >>= 1
            r >>= 1
        return res

N,K,M=map(int,input().split())
A=list(map(int,input().split()))

imos=[A[i] for i in range(N)]
for i in range(1,N):
    imos[i]+=imos[i-1]

data=[(imos[i],i) for i in range(N)]
data.sort()

dp=[[-10**18 for i in range(N)] for j in range(K)]

init=[-10**18 for i in range(N)]

for i in range(M):
    dp[0][i]=abs(imos[i])

for i in range(1,K):
    Low=[0 for j in range(N)]
    High=[0 for j in range(N)]
    lowseg=SegTree(init,segfunc,ide_ele)
    highseg=SegTree(init,segfunc,ide_ele)
    for j in range(N):
        val,id=data[j]
        L=max(id-M,i-1)
        R=id
        Low[id]=lowseg.query(L,R)+val
        lowseg.update(id,dp[i-1][id]-imos[id])
    for j in range(N-1,-1,-1):
        val,id=data[j]
        L=max(id-M,i-1)
        R=id
        High[id]=highseg.query(L,R)-val
        highseg.update(id,dp[i-1][id]+imos[id])

    for j in range(i,N):
        dp[i][j]=max(Low[j],High[j])

print(dp[K-1][N-1])