#include<fstream.h>
int main()
{ifstream f("subsir2.in");
ofstream h("subsir2.out");
int d[550],n,a[1000],i,j,min=550,ok=0,o;
f>>n;
for(i=1;i<=n;i++)
	{f>>a[i];
d[i]=0;}
d[n]=1;
for(i=n-1;i>=1;i=i-1)
	{for(j=i;j<=n;j++)
		if(d[i]<d[j]+1&&a[i]<=a[j])
			d[i]=d[j]+1;
	        for(o=i-1;o>=1;o=o-1)
				if(a[o]<=a[i])
					{ok=0;
				break;}
	if(ok==1&&d[i]<min)
		{min=d[i];
	ok=0;}
	ok=1;
	}
	h<<min;
return 0;}