#include <bits/stdc++.h>
using namespace std;

int main() {
int n;
cin>>n;
vector<long long>vec(n+1);
long long a[n];
for (int i = 0; i < n; ++i) {
	cin>>a[i];
	vec[a[i]]++;
}
int counter=0;
for (int j = 0; j < n; ++j) {
	if(vec[a[j]]==1){
		counter+=1;
	}
}
cout<<counter<<endl;
}