N=int(input())
A=list(map(int,input().split()))
inf=1<<30
ans=inf
for i in range(1,101):
    if i*i>sum(A):
        break
    lst=list(range(1,i+1))+list(range(i-1,0,-1))
    ans=min(ans,sum(A)-sum(min(a,c) for a,c in zip(A,lst)))
print(ans)