#include <iostream>

using namespace std;

int main(){
	int n;
	while(cin>>n){
		if(n == -1) break;
		int dp[n+1][n+1][n+1] = { 0 };
		int arr[n+1];
		for(int i=0;i<n;i++){
			cin>>arr[i+1];
		}
		for(int k=1;k<n+1;k++) for(int i=0;i<k+1;i++) for(int j=0;j<k+1;j++){
				if(i != k and j != k){
				dp[k][i][j] = dp[k-1][i][j]; // no pinto nada
				if(i==0) dp[k][k][j] = max(dp[k][k][j],dp[k-1][i][j]+1);
				else if(arr[k] > arr[i]) dp[k][k][j] = max(dp[k][k][j],dp[k-1][i][j] + 1);
				if(j==0) dp[k][i][k] = max(dp[k][i][k],dp[k][i][j] +1);
				else if(arr[k] < arr[j]) dp[k][i][k] = max(dp[k][i][k],dp[k-1][i][j] +1);
				}
		}
		int answer = 0;
		for(int i=0;i<n+1;i++) for(int j=0;j<n+1;j++){
			answer = max(answer, dp[n][i][j]);
		}
		cout<<n-answer<<endl;
		}
}