import sys
input = sys.stdin.readline

from heapq import heappop,heappush

N=int(input())
A=list(map(int,input().split()))

A.sort(reverse=True)

OK=10**5
NG=0

while OK>NG+1:
    mid=(OK+NG)//2

    H=[]
    for a in A:
        heappush(H,-a)

    for i in range(mid-1,-1,-1):
        if i>=65:
            d=10**18
        else:
            d=(1<<i)

        x=-heappop(H)

        x-=d

        if x>0:
            heappush(H,-x)

        if len(H)==0:
            break

    if len(H)==0:
        OK=mid
    else:
        NG=mid

print(OK)