n,m = map(int,input().split())
w = list(map(int,input().split()))
t = 0

def jiancha(a):
    for i in range(len(a)):
        if 0 in a:
            a.remove(0)
        elif 0 not in a:
            break

flag = 0
while len(w)>m:
    t += 1
    for i in range(m):
        if w[i] < 1:
            continue
        else:
            w[i]-=1
    jiancha(w)
if len(w)<=m:
    t += max(w)  
print(t)