import heapq

N, M = (int(x) for x in input().split())
T=list(map(int, input().split()))
L=[]
heapq.heapify(L)
for i in range(1, M+1):
    heapq.heappush(L, (0, i))

for i in T:
    p, idx = heapq.heappop(L)
    heapq.heappush(L, (p+i, idx))

ans = 0
while L:
    p, idx = heapq.heappop(L)
    ans = max(ans, p)

print(ans)