def dfs(n, g):
    if g[n] is not None:
        gg = g[n]
        g[n] = None
        for adj in gg:
            dfs(adj, g)
        return 1
    return 0


a = [int(input())-1 for _ in range(int(input()))]
graph = [[] for _ in range(len(a))]
for i in range(len(a)):
    graph[i].append(a[i])
    graph[a[i]].append(i)
cmp = 0
for i in range(len(a)):
    cmp += dfs(i, graph)

print(len(a)-len(set(a)) + (0 if cmp == 1 else cmp))