//inlclude前用define #define _USE_MATH_DEFINES //include #include<iostream> #include<string> #include<algorithm> #include<vector> #include<cmath> #include<cstdio> #include<type_traits> #include<numeric> #include<limits> #include<iomanip> using namespace std; //typedef typedef vector<int> VI; typedef vector<string> VS; typedef vector<char> VC; //grobal変数 int main() { int n; cin >> n; VI a(n+2); for (int i = 1; i <= n; i++) cin >> a[i]; sort(a.begin(), a.end()); int cnt = 0; for (int i = 1; i <= n; i++) { if (a[i] != a[i - 1] && a[i] != a[i + 1]) { cnt++; } } cout << cnt << endl; return 0; }