#25150: python AC
ianhikakin@gmail.com
(以恩)
people=int(input())
fdlist= list(map(int,input().split(' ')))
final=0
oldsmallin=0#舊暫存
smallin=0#新暫存
for i in range(people):
oldsmallin=i
smallin=i
if fdlist[i]!=-1:
while fdlist[smallin]!=-1:
smallin=fdlist[oldsmallin]
fdlist[oldsmallin]=-1
oldsmallin=smallin
final+=1
print(final)