#include<bits/stdc++.h>
using namespace std;
const int N=1e5+1;
int a[N],dp[N],dp1[N],n1,k; 
int main(){
	scanf("%d",&n1);
    for(int i=1;i<=n1;i++)scanf("%d",&a[i]);
	int ans=0,maxn=0;
	int n=n1/2;
    for(int i=1;i<=n;i++){
        dp[i]=1;
		for(int j=1;j<=i-1;j++){
			if(a[j]<a[i])dp[i]=max(dp[i],dp[j]+1);
		}maxn=max(dp[i],maxn);
	}ans+=n-maxn;
	int max2=0;
	for(int i=n;i<=n1;i++){
	    dp1[i]=1;
		for(int j=n;j<=i-1;j++){
			if(a[j]>a[i])dp1[i]=max(dp1[i],dp1[j]+1);
		}maxn=max(maxn,dp1[i]);
	}ans+=n-max2;
	printf("%d\n",ans/2+1);
    return 0;
}