#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned int uint;
typedef unsigned char uchar;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define REP(i,x) for(int i=0;i<(int)(x);i++)
#define REPS(i,x) for(int i=1;i<=(int)(x);i++)
#define RREP(i,x) for(int i=((int)(x)-1);i>=0;i--)
#define RREPS(i,x) for(int i=((int)(x));i>0;i--)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();i++)
#define RFOR(i,c) for(__typeof((c).rbegin())i=(c).rbegin();i!=(c).rend();i++)
#define ALL(container) (container).begin(), (container).end()
#define RALL(container) (container).rbegin(), (container).rend()
#define SZ(container) ((int)container.size())
#define mp(a,b) make_pair(a, b)
#define pb push_back
#define eb emplace_back
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );
#define __builtin_popcount __builtin_popcountll

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
    os<<"["; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"]"; return os;
}
template<class T> ostream& operator<<(ostream &os, const set<T> &t) {
    os<<"{"; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"}"; return os;
}
template<class S, class T> ostream& operator<<(ostream &os, const map<S, T> &t) {
    os<<"{"; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"}"; return os;
}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
template<class S, class T> pair<S,T> operator+(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first+t.first, s.second+t.second);}
template<class S, class T> pair<S,T> operator-(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first-t.first, s.second-t.second);}

const int INF = 1<<28;
const double EPS = 1e-8;
const int MOD = 1000000007;


int n;
vector<ll> solve(vi d) {
    vector<ll> dp;
    dp.push_back(0);
    ll cur = 0;
    ll last = MOD;
    vector<pii> t; // *4 , count
    t.emplace_back(MOD, 0);
    RREP(i, n) {
        ll x = d[i];
        while(x > last) {
            int c4, cnt; tie(c4, cnt) = t.back(); t.pop_back();
            cur += 2 * cnt;
            c4 --;
            if (c4 > 0) {
                t.emplace_back(c4, cnt);
            } else {
                t.back().second += cnt;
            }
            last *= 4;
        }
        if (x * 4 > last) {
            t.back().second ++;
        } else {
            ll j = 0, y = x;
            while(y * 4 <= last) {
                j ++;
                y *= 4;
            }
            t.emplace_back(j, 1);
        }
        last = x;
        dp.push_back(cur);
    }
    return dp;
}

int main(int argc, char *argv[]){
    ios::sync_with_stdio(false);
    while (cin >> n) {
        vi d(n);
        REP(i, n) cin >> d[i];
        vector<ll> dp1 = solve(d);
        reverse(ALL(d));
        vector<ll> dp2 = solve(d);
        ll ans = 1ll << 60;
        REP(i, n + 1) {
            ans = min(ans, dp2[i] + dp1[n - i] + i);
        }
        cout << ans << endl;
    }
    return 0;
}


Measured memory_bytes: 6496