import heapq
from itertools import accumulate

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

X = [[] for _ in range(K+1)]
Y = [[] for _ in range(K+1)]
for i in range(K):
    X[i].append((0, N+1))
    Y[i].append((0, N+1))

dp = [[0] * (K + 1) for _ in range(N + 1)]
for i, b in enumerate(B, 1):
    L = max(0, i - M)
    for j in reversed(range(1, K + 1)):
        while X[j-1] and X[j-1][0][1] < L:
            heapq.heappop(X[j-1])
        while Y[j-1] and Y[j-1][0][1] < L:
            heapq.heappop(Y[j-1])
        val = 0
        val = max(val, b - X[j-1][0][0])
        val = max(val, -Y[j-1][0][0] - b)
        dp[i][j] = val
        heapq.heappush(X[j], (-(val - b), i))
        heapq.heappush(Y[j], (-(val + b), i))

print(dp[N][K])