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):
    queue = [sortedl]
    while queue:
        queue.sort(key=lambda l: sum([ p[1] for p in l[:num_subl] ]))
        checking = queue.pop(0)
        if is_valid(num_subl, [ p[0] for p in checking[:num_subl] ]):
            agenda.append(sum([ p[1] for p in checking[:num_subl] ]))
            break
        if len(checking)>num_subl:
            for i in range(num_subl):
                queue.append(checking[:i]+checking[i+1:])
print(min(agenda))