flag=0
t=0
tap=0
nums=list(map(int,input().split()))
l=list(map(int,input().split()))
if nums[0]<=nums[1]:
print(max(l))
else:
while :
tap=0
for i in range(nums[1]):
l[i]-=1
if l[i]==0 and (nums[1]+flag)<nums[0]:
l[i]=l[nums[1]+flag]
l[nums[1]+flag]=0
flag+=1
else:
pass
t+=1
for i in l:
if i<=0:
tap+=1
if tap==nums[0]:
break
print(t)
