#include <iostream>
#include <string>
#include <cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<iomanip>
#define _USE_MATH_DEFINES
#include <math.h>
#include <functional>
#include<complex>
using namespace std;

#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)

typedef long long ll;
const ll INF = 1e17;
const ll MOD = 1000000007;
const ll MAX = 4000001;
const double eps = 1E-18;

ll max(ll a, ll b) {
	if (a > b) { return a; }
	return b;
}

ll min(ll a, ll b) {
	if (a > b) { return b; }
	return a;
}

ll gcd(ll a, ll b) {
	if (b == 0) { return a; }
	if (a < b) { return gcd(b, a); }
	return gcd(b, a % b);
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

struct edge {
	ll ind;
	ll fr;
	ll to;
	ll d;
};

class mint {
	long long x;
public:
	mint(long long x = 0) : x((x% MOD + MOD) % MOD) {}
	mint operator-() const {
		return mint(-x);
	}
	mint& operator+=(const mint& a) {
		if ((x += a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator-=(const mint& a) {
		if ((x += MOD - a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator*=(const  mint& a) {
		(x *= a.x) %= MOD;
		return *this;
	}
	mint operator+(const mint& a) const {
		mint res(*this);
		return res += a;
	}
	mint operator-(const mint& a) const {
		mint res(*this);
		return res -= a;
	}
	mint operator*(const mint& a) const {
		mint res(*this);
		return res *= a;
	}

	mint operator^(const ll& t)const {
		if (!t) return 1;
		mint a = pow(t >> 1);
		a *= a;
		if (t & 1) a *= *this;
		return a;
	}

	mint pow(ll t) const {
		if (!t) return 1;
		mint a = pow(t >> 1);
		a *= a;
		if (t & 1) a *= *this;
		return a;
	}
	// for prime MOD
	mint inv() const {
		return pow(MOD - 2);
	}
	mint& operator/=(const mint& a) {
		return (*this) *= a.inv();
	}
	mint operator/(const mint& a) const {
		mint res(*this);
		return res /= a;
	}

	friend ostream& operator<<(ostream& os, const mint& m) {
		os << m.x;
		return os;
	}
};

///////////////////////////


int main() {
	ll N;
	cin >> N;
	vector<ll> A(N + 1);
	repn(i, N) cin >> A[i];

	vector<vector<ll>> pos(N + 2, vector<ll>(20, 0));
	vector<vector<ll>> neg(N + 2, vector<ll>(20, 0));

	rep(j, 20) {
		pos[N][j] = j;
		neg[1][j] = j;
	}

	
	for (ll i = N - 1; i >= 1; i--) {

		ll c = 0;
		for (ll x = A[i + 1]; A[i] > x; x *= 4) {
			c++;
		}

		ll d = 0;
		for (ll x = A[i]; A[i+1] >= 4*x; x *= 4) {
			d++;
		}

		rep(j, 20) {
			if (j < d) { pos[i][j] = pos[i + 1][j] + j; }
			else {
				ll k = j + c - d;
				if (k < 20) { pos[i][j] = pos[i + 1][k] + j; }
				else { pos[i][j] = pos[i + 1][19] + (k - 19)*(N - i) + j; }
			}

			//cout << i << " " << j << " " << pos[i][j] << endl;
		}

	}
	

	for (ll i = 2; i <= N; i++) {

		ll c = 0;
		for (ll x = A[i - 1]; A[i] > x; x *= 4) {
			c++;
		}

		ll d = 0;
		for (ll x = A[i]; A[i - 1] >= 4 * x; x *= 4) {
			d++;
		}

		rep(j, 20) {
			if (j < d) { neg[i][j] = neg[i - 1][j] + j; }
			else {
				ll k = j + c - d;
				if (k < 20) { neg[i][j] = neg[i - 1][k] + j; }
				else { neg[i][j] = neg[i - 1][19] + (k - 19)*(i - 1) + j; }
			}
		}

	}

	ll ans = INF;
	rep(i, N + 1) {
		ans = min(ans, i+2*neg[i][0] + 2*pos[i + 1][0]);
	}
	cout << ans << endl;
	
	system("PAUSE");
}


Measured memory_bytes: 80128