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

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 
#define GETLINE_SEPARATE( A , SEPARATOR ) string A; getline( cin , A , SEPARATOR ) 
#define FOR_LL( VAR , INITIAL , FINAL_PLUS_ONE ) for( ll VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ ) 
#define REPEAT( HOW_MANY_TIMES ) FOR_LL( VARIABLE_FOR_REPEAT , 0 , HOW_MANY_TIMES ) 
#define RETURN( ANSWER ) cout << ( ANSWER ) << endl; return 0 
#define DOUBLE( PRECISION , ANSWER ) cout << fixed << setprecision( PRECISION ) << ( ANSWER ) << endl; return 0 
#define MIN( A , B ) A < B ? A : B 
#define MAX( A , B ) A < B ? B : A 

template <typename T> inline T Absolute( const T& a ){ return a > 0 ? a : - a; }

constexpr const ll P = 1000000007;

int main(){
  CIN( ll , N );
  ll N_plus = N + 1;
  ll A[100002];
  A[0] = 0;
  FOR_LL( i , 1 , N_plus ){
    cin >> A[i];
  }
  A[N_plus] = 1000000001;
  sort( A + 1 , A + N_plus );
  ll answer = 0;
  FOR_LL( i , 1 , N_plus ){
    ll& Ai = A[i];
    if( A[i - 1] != Ai && Ai != A[i + 1] ){
      answer++;
    }
  }
  RETURN( answer );
}