if __name__ == "__main__":
    n = int(input())
    num_list = list(map(int, input().split(" ")))
    num_cnt_list = [0] * n
    for i in range(n):
        num_cnt_list[num_list[i] - 1] += 1
    j = 0
    ans = 0
    while j < n:
        if 1 < num_cnt_list[j]:
            zero_pos = num_cnt_list.index(0)
            num_cnt_list[j] -= 1
            num_cnt_list[zero_pos] += 1
            ans += abs(zero_pos - j)
            j = 0
        else:
            j += 1
    print(ans)