import sys
input = sys.stdin.buffer.readline

def main():

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

    n = 10**4+1

    def segfunc(x, y):
        return min(x, y)

    def init(init_val):
        # set_val
        for i in range(n):
            seg[i+num-1] = init_val[i]
        # built
        for i in range(num-2, -1, -1):
            seg[i] = segfunc(seg[2*i+1], seg[2*i+2])

    def update(k, x):
        k += num - 1
        seg[k] = x
        while k:
            k = (k-1)//2
            seg[k] = segfunc(seg[2*k+1], seg[2*k+2])

    def query(p, q):
        if q <= p:
            return ide_ele
        p += num - 1
        q += num - 2
        res = ide_ele
        while q-p>1:
            if p&1 == 0:
                res = segfunc(res, seg[p])
            if q&1 == 1:
                res = segfunc(res, seg[q])
                q -= 1
            p = p//2
            q = (q-1)//2
        if p == q:
            res = segfunc(res, seg[p])
        else:
            res = segfunc(segfunc(res, seg[p]), seg[q])
        return res

    # identity element
    ide_ele = 10**18

    # num: n以上の最小の2のべき乗
    num = 2**(n-1).bit_length()
    seg = [ide_ele]*2*num

    dp = [0]*n
    import copy
    for i in range(N):
        init(dp)
        temp = [0]*n
        for j in range(n):
            temp[j] = query(0, j+1)+abs(j-Y[i])
        dp = copy.copy(temp)
    print(min(dp))

if __name__ =='__main__':
    main()