#include<bits/stdc++.h>

#define rep(i,n) for(int i=0;i<n;i++)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define each(it,v) for(auto &it : v)
#define all(v) (v).begin(),(v).end()

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;
using Pii = pair<int,int>;
using Pll = pair<ll,ll>;
using vpii = vector<Pii>;
using vpll = vector<Pll>;

const ll mod=1e9+7;
const int intINF=INT_MAX;
const ll  longINF=LONG_LONG_MAX;

main()
{
        int n; cin>>n;

        map<int,int> m;
        rep(i,n)
        {
                int a; cin>>a;
                m[a]++;
        }

        int ans=0;
        each(it,m)
        {
                if(it.second==1)ans++;
        }
        cout<<ans<<endl;
}