import sys
sys.setrecursionlimit(100000000)

N, K = map(int, input().split())
prices = list(map(int, input().split()))
INF = 10000000000

memo = {}

def minPrice(n, k):
    if (n, k) in memo:
        return memo[(n, k)]
    if n < k:
        return INF
    if k == 0:
        return 0
    if k == 1:
        return min(prices)
    take = prices[n-1] + minPrice(n-1, k-1)
    skip = minPrice(n-1, k)
    ans = min(INF, take, skip)
    memo[(n, k)] = ans
    return ans

print(minPrice(N, K))