N=int(input()) A=list(map(int, input().split())) D=[[] for i in range(N)] P=[-1]*N for i in range(N): if A[i]!=0: D[i].append(A[i]-1) P[A[i]-1]=i ans=0 for i in range(N): if P[i]==-1: for j in D[i]: ans+=len(D[j]) print(ans)