import heapq

N, K = [ int(a) for a in input().split(' ') ]
alist = [ int(a) for a in input().split(' ') ]

def is_valid(num_subl, inds):
    inds = sorted(inds)
    prev = -1
    for i in range(num_subl):
        start = max(prev+1, K*(i+1)-1)
        end = min(start+(num_subl-i-1)*(K-1)+ (N-num_subl*K if i > 0 else 0), N-(num_subl-i-1)-1)
        if inds[i] not in range(start,end+1):
            return False
        prev = inds[i]
    return True

agenda = []
enumed = list(enumerate(alist))
sortedl = sorted(enumed, key=lambda p:p[1])
for num_subl in range(1,N//K+1):
    if num_subl > 1:
        if min(agenda) < sum([ p[1] for p in sortedl[:num_subl] ]):
            break
    queue = []
    heapq.heappush(queue,(sum([ p[1] for p in sortedl[:num_subl] ]), tuple(sortedl)))
    while queue:
        sumc, checking = heapq.heappop(queue)
        if is_valid(num_subl, [ p[0] for p in checking[:num_subl] ]):
            agenda.append(sumc)
            break
        if len(checking)>num_subl:
            for i in range(num_subl):
                new_checking = checking[:i]+checking[i+1:]
                heapq.heappush(queue, (sum([ p[1] for p in new_checking[:num_subl] ]), new_checking))
print(min(agenda))