#include <bits/stdc++.h>
using namespace std;
#define rep(i, n)  for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define all(a) a.begin(),a.end()
#define pb emplace_back
#define eb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
#define ub(v,k) (upper_bound(all(v),k)-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define dupli(a) a.erase(unique(all(a)),a.end())
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
typedef multiset<ll> S;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const int INF=1001001001;
const int mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void noyes(T b){if(b)out("no");else out("yes");}
template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}
template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){a%=mod;if(b==0)return 1;if(b&1)return a*modpow(a,b-1)%mod;ll k=modpow(a,b/2);return k*k%mod;}
vi solve(vi v){
    ll n=v.size();
    vi cnt(n);
    cnt[n-1]=inf;
    rep(i,n-1){
        ll k=v[i];
        while(k*4<=v[i+1]){
            cnt[i]++;
            k*=4;
        }
    }
    deque<ll> c;
    c.push_front(n-1);
    vi res(n);
    for(int i=n-2;i>=0;i--){
        res[i]=res[i+1];
        if(v[i]>v[i+1]){
            ll k=v[i+1];
            while(k<v[i]){
                cnt[i+1]--;k*=4;res[i]++;
            }
            if(cnt[i+1]>0)c.push_front(i+1);
            else{
                int b=i+1;
                ll r=-cnt[i+1];
                chmax(cnt[i+1],0ll);
                while(true){
                    int j=c.front();
                    res[i]+=r*(j-b);
                    if(cnt[j]>=r){
                        cnt[j]-=r;break;
                    }
                    r-=cnt[j];
                    cnt[j]=0;
                    c.pop_front();
                    b=j;
                }
            }
        }
        if(cnt[i]>0)c.push_front(i);
    }
    return res;
}
int main(){
    ll n;cin>>n;
    vi v(n);
    rep(i,n)cin>>v[i];
    vi a=solve(v);
    reverse(all(v));
    vi b=solve(v);
    reverse(all(b));
    rep(i,n){
        a[i]*=2;
        b[i]*=2;
        b[i]+=i+1;
    }
    ll ans=min(a[0],b[n-1]);
    rep(i,n-1)chmin(ans,a[i+1]+b[i]);
    out(ans);
}

Measured memory_bytes: 8008