n,m,t,*a=map(int,open(0).read().split())
def judge(x):
  d=[0]*n
  r=0
  for i in a:
    if d[i-1]+1<=x:
      d[i-1]+=1
    else:
      r+=1
  for i in d:
    if r<=0:
      break
    if i+t<=x:
      nr=(x-i)//t
      r-=nr
  return r<=0
ok,ng=1<<60,0
while abs(ok-ng)>1:
  mid=ok+ng>>1
  if judge(mid):
    ok=mid
  else:
    ng=mid
print(ok)