#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
class node{
public:
	int ore,num,sor;
}a[1010]={0};
int n,m,x;
void init()
{
	for(int i=1;i<=n;i++)
	{
		a[i].ore=i;
		cin>>a[i].num;
	}
}
int pai(node a,node b)
{
	if(a.num>b.num)
		return 1;
	if(a.num<b.num)
		return 0;
}
int main()
{
	freopen("mark.in","r",stdin);
	freopen("mark.out","w",stdout);
	cin>>n>>m;
	init();
	cin>>x;
	int bb=a[x].num,xx;
	sort(a+1,a+n+1,pai);
	for(int i=1;i<=n;i++)
		if(a[i].num==a[i+1].num)
			a[i].num=-1;
	sort(a+1,a+n+1,pai);
	for(int i=1;i<=n;i++)
	{
		a[i].sor=i;
		if(a[i].num==bb)
			xx=a[i].sor;
	}
	int k=n/m;
	while(xx%k!=0)
		xx=xx+1;
	cout<<xx/k;
	return 0;
}