n,k = map(int,input().split())
c = list(map(int,input().split()))

total = [[0 for _ in range(n)] for _ in range(n)]
for i in range(n):
    total[i][i] = c[i]
for l in range(1,n):
    for i in range(0,n-l):
        j = i+l
        if l<=k:
            total[i][j] = min(c[i:j])
        else:
            minc = 2**64-1
            for m in range(i,j):
                left = m-k
                right = m+k
                cost = c[m]
                if left>i:
                    cost += total[i][left-1]
                if right<j:
                    cost += total[right+1][j]
                if cost<minc:
                    minc = cost
            total[i][j] = minc
#print(total)        
print(total[0][n-1])