생성일: 2022년 1월 14일 오후 5:27
# 뮤직비디오(결정 알고리즘)
import sys
sys.stdin = open("input.txt", "rt")
def Count(capacity):
    sum = 0
    cnt = 1
    for x in music:
        if sum+x > capacity:
            cnt += 1
            sum = x
        else:
            sum += x
    return cnt
n, m = map(int, input().split())
music = list(map(int,input().split()))
maxx = max(music)
lt = 1
rt = sum(music)
res = 0
while lt <= rt:
    mid = (lt+rt)//2
    if mid >= maxx and Count(mid) <= m:
        res = mid
        rt = mid - 1
    else:
        lt = mid + 1
print(res)