#include <cstdio>
#include <memory.h>
using namespace std;

int a[1001],f[1001][2];

int main(void)
{
	freopen("missilea.in","r",stdin);
	freopen("missilea.out","w",stdout);
	int i,j,n;
	scanf("%d\n",&n);
	while (n)
	{
		memset(f,0,sizeof(f));
		for (i=1;i<=n;i++)
			scanf("%d",&a[i]);
		for (i=1;i<=n;i++)
		{
			for (j=1;j<i;j++)
			{
				if (a[i]<=a[j])
					continue;
				if (f[i][1]<f[j][0])
					f[i][1]=f[j][0];
			}
			f[i][1]++;
			for (j=1;j<i;j++)
			{
				if (a[i]>=a[j])
					continue;
				if (f[i][0]<f[j][1])
					f[i][0]=f[j][1];
			}
			if (f[i][0])
				f[i][0]++;
		}
		if (f[n][0]<f[n][1])
			f[n][0]=f[n][1];
		printf("%d\n",f[n][0]);
		scanf("%d\n",&n);
	}
	return(0);
}