from collections import deque

N, B, C = map(int, input().split())
A = list(map(int, input().split()))
t = 0
k = 0
d = deque()
e = deque()
for i, a in enumerate(A):
    if d:
        u = e[0][0] + k
    else:
        u = -(10**18)
    if B > 2 or i == 0:
        u = max(u, t)
    d.append((t - k, i))
    e.append((t - k, i))
    while len(e) >= 2 and e[-2] < e[-1]:
        x = e.pop()
        e.pop()
        e.append(x)
    k += a
    while len(d) >= C:
        x = d.popleft()
        if len(e) > 0 and e[0] == x:
            e.popleft()
    t = u
print(max(t, max(d)[0] + k))