from collections import deque

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

C=[i for i in range(N) if not B[i]]
D=[i for i in range(N) if B[i]]

C=deque(C)
D=deque(D)

X=0
while C:
    while B[D[0]]==1:
        _=D.popleft()

    c=C.popleft()
    X+=abs(c-D[0])
    B[D[0]]-=1
    B[c]+=1

print(X)