# Original solution
#      
import collections, atexit, math, sys, bisect 

sys.setrecursionlimit(1000000)
def getIntList():
    return list(map(int, input().split()))    

try :
    #raise ModuleNotFoundError
    import numpy
    def dprint(*args, **kwargs):
        #print(*args, **kwargs, file=sys.stderr)
        # in python 3.4 **kwargs is invalid???
        print(*args,  file=sys.stderr)
    dprint('debug mode')
except Exception:
    def dprint(*args, **kwargs):
        pass



inId = 0
outId = 0
if inId>0:
    dprint('use input', inId)
    sys.stdin = open('input'+ str(inId) + '.txt', 'r') #标准输出重定向至文件
if outId>0:
    dprint('use output', outId)
    sys.stdout = open('stdout'+ str(outId) + '.txt', 'w') #标准输出重定向至文件
    atexit.register(lambda :sys.stdout.close())     #idle 中不会执行 atexit


if True:
    N, = getIntList()
    #print(N)
    za = getIntList()
else:
    N = 1000
    import random
    za = [random.randint(1, 1000000000) for i in range(N) ]

dprint('begin')

zleft = [0 for i in range(N+1)]
zright = [0 for i in range(N+1)]


def getwork(zr, za):
    zr[0] = 0
    st = []
    for i in range(N):
        if i%10000  ==0:
            dprint('---', i)
        nt = [[za[i],0], [za[i],0], 1]
        st.append(nt)
        nr = zr[i]
        #dprint(st)
        while len(st)>1:
            b_2 = st[-2][1][1]
            b_1 = st[-1][0][1]
            bb = min(b_1,b_2)
            b_1 -=bb
            b_2 -=bb
            b_1p = 4 ** b_1
            b_2p = 4 ** b_2
            t2 = st[-2][1][0] * b_2p
            t1 = st[-1][0][0] * b_1p
            if  t2 < t1:
                nr+= 2* st[-2][2]
                st[-2][0][1] +=1
                st[-2][1][1] +=1
            elif t2 < t1 * 4:
                ttt = [ st[-2][0], st[-1][1], st[-2][2] + st[-1][2] ]  
                st[-2] = ttt
                st.pop()
            else:
                break
        #dprint(st)
        zr[i+1] = nr
        #dprint(nr)
        #dprint(st)
        assert nr < 1000000000000000

getwork(zleft, za)
dprint('!!!!')
getwork(zright, za[::-1])
 
#dprint(zleft)
#dprint(zright)

r =  zright[N]
for i in range(N+1):
    tr =  i + zleft[i] + zright[N-i]
    r = min(r,tr)

print(r)

dprint('end')




# Optimized solution
#      
import collections, atexit, math, sys, bisect 

sys.setrecursionlimit(1000000)
def getIntList():
    return list(map(int, input().split()))    

try :
    #raise ModuleNotFoundError
    import numpy
    def dprint(*args, **kwargs):
        #print(*args, **kwargs, file=sys.stderr)
        # in python 3.4 **kwargs is invalid???
        print(*args,  file=sys.stderr)
    dprint('debug mode')
except Exception:
    def dprint(*args, **kwargs):
        pass



inId = 0
outId = 0
if inId>0:
    dprint('use input', inId)
    sys.stdin = open('input'+ str(inId) + '.txt', 'r') #标准输出重定向至文件
if outId>0:
    dprint('use output', outId)
    sys.stdout = open('stdout'+ str(outId) + '.txt', 'w') #标准输出重定向至文件
    atexit.register(lambda :sys.stdout.close())     #idle 中不会执行 atexit


if True:
    N, = getIntList()
    #print(N)
    za = getIntList()
else:
    N = 100
    import random
    za = [random.randint(1, 1000000000) for i in range(N) ]

dprint('begin')

zleft = [0 for i in range(N+1)]
zright = [0 for i in range(N+1)]


def getwork(zr, za):
    zr[0] = 0
    st = []
    for i in range(N):
        if i%10000  ==0:
            dprint('---', i)
        nt = [[za[i],0], [za[i],0], 1]
        st.append(nt)
        nr = zr[i]
        #dprint(st)
        while len(st)>1:
            b_2 = st[-2][1][1]
            b_1 = st[-1][0][1]
            bb = min(b_1,b_2)
            b_1 -=bb
            b_2 -=bb
            b_1p = 4 ** b_1
            b_2p = 4 ** b_2
            t2 = st[-2][1][0] * b_2p
            t1 = st[-1][0][0] * b_1p
            if  t2 < t1:
                nr+= 2* st[-2][2]
                st[-2][0][1] +=1
                st[-2][1][1] +=1
            elif t2 < t1 * 4:
                ttt = [ st[-2][0], st[-1][1], st[-2][2] + st[-1][2] ]  
                st[-2] = ttt
                st.pop()
            else:
                break
        #dprint(st)
        zr[i+1] = nr
        #dprint(nr)
        #dprint(st)
        assert nr < 1000000000000000
    dprint(st)
getwork(zleft, za)
dprint('!!!!')
getwork(zright, za[::-1])
 
#dprint(zleft)
#dprint(zright)

r =  zright[N]
for i in range(N+1):
    tr =  i + zleft[i] + zright[N-i]
    r = min(r,tr)

print(r)

dprint('end')