#include<bits/stdc++.h>
#include <atcoder/all>
#ifdef LOCAL
#include <debug_print.hpp>
#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (static_cast<void>(0))
#endif
using namespace atcoder;
using mint=modint998244353;
using namespace std;
using ll=long long;
using ul=unsigned long long;
int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1};
int dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};
using Graph=vector<vector<int>>;
int main(){
    int N;
    cin>>N;
    map<int,int>mp;
    for(int i=0;i<N;i++){
        int a;
        cin>>a;
        mp[a]++;
    }
    int cnt=0;
    for(auto[k,v]:mp)if(v==1)cnt++;
    cout<<cnt<<endl;
}