#include<stdio.h>
#include<stdlib.h>
#define NMAX 5000

int n,a[NMAX+1];
int m[NMAX+1],M[NMAX+1],next[NMAX+1],l[NMAX+1];


int main(){
freopen("subsir2.in","r",stdin);
freopen("subsir2.out","w",stdout);
int i,j,lmin,lmax,first,ua,pua;
//char sir[NMAX*11],*p;
scanf("%d\n",&n);
for(i=1;i<=n;++i) scanf("%d",&a[i]);
/*fgets(sir,NMAX*11,stdin);p=sir;
for(i=1;i<=n;++i){
	a[i]=atoi(p);
	while(*p!=32) ++p;
	++p;
	} */
int ales=0;
M[n]=1;
for(i=n-1;i;--i){
	lmin=0;ua=a[i];pua=i;ales=0;
	for(j=i+1;j<=n;++j)
		if(a[i]<=a[j]){
			if(!ales){
				lmin=M[j];next[i]=j;
				ua=a[j];pua=j;
				ales=1;
				}
			else
				if(ua>a[j])
					if(lmin>M[j]){
						lmin=M[j];next[i]=j;
						ua=a[j];pua=j;
						}
				}
	M[i]=lmin+1;
	}
m[1]=1;
for(i=2;i<=n;++i){
	lmin=0;ua=a[i];pua=i;ales=0;
	for(j=i-1;j;--j)
		if(a[j]<=a[i]){
			if(!ales){
				lmin=m[j];next[i]=j;
				ua=a[j];pua=j;
				ales=1;
				}
			else
				if(ua<a[j])
					if(lmin>m[j]){
						lmin=m[j];next[i]=j;
						ua=a[j];pua=j;
						}
				}
	m[i]=lmin+1;
	}
for(i=1;i<=n;++i) l[i]=m[i]+M[i]-1;


lmin=n;


for(i=1;i<=n;++i)
	if(lmin>m[i]) {lmin=l[i];first=i;}
	else if(lmin==l[i]&&a[first]>a[next[i]])
			first=i;

printf("%d\n",lmin);
/*i=first;
while(next[i]){
	printf("%d ",i);
	i=next[i];
	}
printf("%d",i); */
return 0;
}