#include<bits/stdc++.h>
#define int long long int
using namespace std;
int dp[10002000],a[10002003];
signed main(){
	int n;
	cin>>n;
	memset(dp,0x3f,sizeof(dp));
	dp[0]=0;
	dp[1]=0;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	int cnt=0;
	for(int i=2;i<=n;i++){
		if(a[i]<=a[i-1]){
			int l=i-1;
			while(a[i]>a[l]){
				 i++;
			}
			dp[i]=min((i-l)+dp[l],dp[i]);
			
		}
		else dp[i]=dp[i-1];
			}
	
	cout<<dp[n];
	return 0;
}