#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

using ll=int64_t;
#define int ll

#define FOR(i,a,b) for(int i=int(a);i<int(b);i++)
#define REP(i,b) FOR(i,0,b)
#define MP make_pair
#define PB push_back
#define EB emplace_back
#define ALL(x) x.begin(),x.end()
auto& errStream=cerr;
#ifdef LOCAL
#define cerr (cerr<<"-- line "<<__LINE__<<" -- ")
#else
class CerrDummy{}cerrDummy;
template<class T>
CerrDummy& operator<<(CerrDummy&cd,const T&){
	return cd;
}
using charTDummy=char;
using traitsDummy=char_traits<charTDummy>;
CerrDummy& operator<<(CerrDummy&cd,basic_ostream<charTDummy,traitsDummy>&(basic_ostream<charTDummy,traitsDummy>&)){
	return cd;
}
#define cerr cerrDummy
#endif
#define REACH cerr<<"reached"<<endl
#define DMP(x) cerr<<#x<<":"<<x<<endl
#define ZERO(x) memset(x,0,sizeof(x))
#define ONE(x) memset(x,-1,sizeof(x))

using pi=pair<int,int>;
using vi=vector<int>;
using ld=long double;

template<class T,class U>
ostream& operator<<(ostream& os,const pair<T,U>& p){
	os<<"("<<p.first<<","<<p.second<<")";
	return os;
}

template<class T>
ostream& operator <<(ostream& os,const vector<T>& v){
	os<<"{";
	REP(i,(int)v.size()){
		if(i)os<<",";
		os<<v[i];
	}
	os<<"}";
	return os;
}

ll read(){
	ll i;
	scanf("%"  SCNd64,&i);
	return i;
}

void printSpace(){
	printf(" ");
}

void printEoln(){
	printf("\n");
}

void print(ll x,int suc=1){
	printf("%" PRId64,x);
	if(suc==1)
		printEoln();
	if(suc==2)
		printSpace();
}

string readString(){
	static char buf[3341000];
	scanf("%s",buf);
	return string(buf);
}

char* readCharArray(){
	static char buf[3341000];
	static int bufUsed=0;
	char* ret=buf+bufUsed;
	scanf("%s",ret);
	bufUsed+=strlen(ret)+1;
	return ret;
}

template<class T,class U>
void chmax(T& a,U b){
	if(a<b)
		a=b;
}

template<class T,class U>
void chmin(T& a,U b){
	if(b<a)
		a=b;
}

template<class T>
T Sq(const T& t){
	return t*t;
}

#define CAPITAL
void Yes(bool ex=true){
	#ifdef CAPITAL
	cout<<"YES"<<endl;
	#else
	cout<<"Yes"<<endl;
	#endif
	if(ex)exit(0);
}
void No(bool ex=true){
	#ifdef CAPITAL
	cout<<"NO"<<endl;
	#else
	cout<<"No"<<endl;
	#endif
	if(ex)exit(0);
}

const ll infLL=LLONG_MAX/3;

#ifdef int
const int inf=infLL;
#else
const int inf=INT_MAX/2-100;
#endif

struct Wafrelka{
	int ans,last;
	vector<pi> buf;
	Wafrelka(){
		ans=0;
		last=-1;
	}
	void Push(int v){
		if(last==-1){
			buf.EB(1,inf);
		}else{
			if(last>=v){
				int x=0;
				while(last>=v*(int(1)<<((x+1)*2)))
					x++;
				buf.EB(1,x);
			}else{
				int x=0;
				while(last*(int(1)<<(x*2))<v)
					x++;
				int s=1;
				while(x){
					int len=buf.back().first,allow=buf.back().second;
					buf.pop_back();
					ans+=x*len;
					s+=len;
					if(allow>=x){
						buf.EB(s,allow-x);
						break;
					}else{
						x-=allow;
					}
				}
			}
		}
		last=v;
	}
	int Get(){
		return ans*2;
	}
};

signed main(){
	int n=read();
	vi a(n);
	REP(i,n)a[i]=read();
	vi waf(n+1,0),relka(n+1,0);
	{
		Wafrelka w;
		REP(i,n+1){
			waf[i]=w.Get();
			if(i<n)
				w.Push(a[i]);
		}
	}
	{
		Wafrelka w;
		for(int i=n;i>=0;i--){
			relka[i]=w.Get();
			if(i-1>=0)
				w.Push(a[i-1]);
		}
	}
	int ans=inf;
	REP(i,n+1){
		chmin(ans,i+waf[i]+relka[i]);
	}
	print(ans);
}


Measured memory_bytes: 10096