def main():
  import sys
  input=sys.stdin.buffer.readline
  from collections import deque
  n,k,m=map(int,input().split())
  a=list(map(int,input().split()))+[0]
  for i in range(n-1,-1,-1):
    a[i]+=a[i+1]
  plus=[deque([]) for j in range(k)]
  plus[0].append((-1,a[0]))
  minus=[deque([]) for j in range(k)]
  minus[0].append((-1,-a[0]))
  for i in range(n):
    for j in range(k-1,-1,-1):
      res=0
      while plus[j] and plus[j][0][0]<i-m:
        plus[j].popleft()
      while minus[j] and minus[j][0][0]<i-m:
        minus[j].popleft()
      if plus[j] and res<plus[j][0][1]-a[i+1]:
        res=plus[j][0][1]-a[i+1]
      if minus[j] and res<minus[j][0][1]+a[i+1]:
        res=minus[j][0][1]+a[i+1]
      if j+1<k:
        while plus[j+1] and plus[j+1][-1][1]<=res+a[i+1]:
          plus[j+1].pop()
        while minus[j+1] and minus[j+1][-1][1]<=res-a[i+1]:
          minus[j+1].pop()
        plus[j+1].append((i,res+a[i+1]))
        minus[j+1].append((i,res-a[i+1]))
      elif i==n-1:
        print(res)
        exit()
main()