from heapq import heappush,heappop
N,M=map(int,input().split())
T=list(map(int,input().split()))
S=[]
for i in range(M):
    heappush(S,(0,i))
for t in T:
    time,s=heappop(S)
    heappush(S,(time+t,i))
ans=0
for time,s in S:
    ans=max(ans,time)
print(ans)