import sys
input = sys.stdin.buffer.readline

import copy

def main():

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

    n = 10**4+1

    dp = [0]*n
    for i in range(N):
        temp = [0]*n
        cum = [10**18]*(n+1)
        for j in range(n):
            cum[j+1] = min(cum[j], dp[j])
        for j in range(n):
            temp[j] = cum[j+1]+abs(j-Y[i])
        dp = copy.copy(temp)
    print(min(dp))

if __name__ =='__main__':
    main()