n = int(input())
A = list(map(int, input().split()))
Counter = [0 for _ in range(n)]
for i in range(n):
    Counter[A[i] - 1] += 1
ans = 0
for i in range(n):
    if Counter[i] == 0:
        idx = -1
        for j in range(n):
            if Counter[j] > 1:
                Counter[j] -= 1
                idx = j
                break
        ans += abs(j - i)
print(ans)