#include<iostream> #include<sstream> #include<cstdio> #include<cstring> #include<algorithm> #include<string> #include<vector> #include<cmath> #include<set> #include<map> #include<stack> #include<queue> #include<numeric> #include<functional> #include<complex> using namespace std; #define BET(a,b,c) ((a)<=(b)&&(b)<(c)) #define FOR(i,n) for(int i=0,i##_end=(int(n));i<i##_end;i++) #define SZ(x) (int)(x.size()) #define ALL(x) (x).begin(),(x).end() #define MP make_pair #define FOR_EACH(it,v) for(__typeof(v.begin()) it=v.begin(),it_end=v.end() ; it != it_end ; it++) typedef vector<int> VI; typedef vector<VI> VVI; int main() { int n; cin>>n; map<int,int> hist; FOR(i,n){ int x; scanf("%d",&x); hist[x]++; } int ans = 0 ; for(auto p : hist){ if(p.second == 1) ans++; } cout<<ans<<endl; return 0; }