N = int(input())
Y = list(map(int, input().split()))
M = 10005
inf = 10 ** 18
pre = [0] * M
Acp = [0] * (M + 1)
for i in range(N):
    dp = [0] * M
    Ac = [inf] * (M + 1)
    for y in range(M):
        dp[y] = Acp[y + 1] + abs(y - Y[i])
        Ac[y + 1] = min(Ac[y], dp[y])
    dp, pre = pre, dp
    Acp, Ac = Ac, Acp

print(min(pre))