n = int(input())
p = list(map(int, input().split()))
visited = [False] * n
count = 0

for i in range(n):
    if not visited[i]:
        cycle_size = 0
        current = i
        while not visited[current]:
            visited[current] = True
            current = p[current] - 1
            cycle_size += 1
        count += (cycle_size - 1)

print(count)