#include<bits/stdc++.h>
using namespace std;
int n,pos,a[100050],ps[100050],p=1;
int ans;
int main()
{
	cin>>n>>pos;
	for(int i=1;i<=n;i++)
		scanf("%d",&a[i]);
	ps[1]=a[1];
	for(int i=2;i<pos;i++)
	{
		if(a[i]>=ps[p])ps[++p]=a[i];
		else{
			int l=1,r=p,mid=p>>1;
			while(l!=r)
			{
				if(ps[mid]<=a[i])l=mid+1;
				else r=mid;
				mid=(l+r)>>1;
			}
			ps[l]=a[i];
		}
	}
	if(ps[p]<=a[pos])
	{
		p++;
	}
	else{
		a[pos]=1e9+1;
	}
	ans=pos-p;
	ps[1]=a[pos];
	p=1;
	for(int i=pos+1;i<=n;i++)
	{
		if(a[i]<=ps[p])ps[++p]=a[i];
		else{
			int l=1,r=p,mid=p>>1;
			while(l!=r)
			{
				if(ps[mid]>=a[i])l=mid+1;
				else r=mid;
				mid=(l+r)>>1;
			}
			ps[l]=a[i];
		}
	}
	ans+=(n-pos+1)-p;
	cout<<ans;
}