def main():
    n=int(input())
    a=list(map(int,input().split()))
    d={}
    for i in a:
        if i in d:
            d[i]+=1
        else:
            d[i]=1
    cnt=0
    for i in d:
        if d[i]==1:
            cnt+=1
    print(cnt)
            
    

if __name__=="__main__":
    main()