def minimum_swaps_to_sort(P):
    N = len(P)
    visited = [False] * N
    P = [x - 1 for x in P]
    
    swaps = 0
    for i in range(N):
        if not visited[i]:
            current = i
            cycle_length = 0
            
            while not visited[current]:
                visited[current] = True
                current = P[current]
                cycle_length += 1
            if cycle_length > 1:
                swaps += cycle_length - 1
    
    return swaps
N = int(input())
P = list(map(int, input().split()))
result = minimum_swaps_to_sort(P)
print(result)