package main

import . "fmt"
import . "sort"

func main() {
	var n,m,t int
	Scan(&n,&m,&t)
	v:=make([]int,n)
	for i:=0;i<m;i++ {
		var a int
		Scan(&a)
		v[a-1]++
	}
	Sort(Reverse(IntSlice(v)))
	x:=Search(1e17,func(i int)bool{
		r:=0
		for _,c:=range v {
			if c>i {
				r+=c-i
			} else {
				z:=i-c
				r=max(0,r-z/t)
			}
		}
		return r==0
	})
	Println(x)
}