#define _USE_MATH_DEFINES	//M_PI(π),M_SQRT2(√2)
#include <iostream>			//std::cout, std::cin
#include <string>			//std::string
#include <vector>			//std::vector
#include <valarray>			//std::valarray
#include <algorithm>		//std::sort
#include <time.h>			//localtime_s
#include <cstdlib>			//abs
#include <cmath>			//abs,std::pow,sqrt,sin,cos,round,floor,ceil
#include <fstream>			//std::ifstream
#include <iomanip>			//std::setprecision
#include <random>			//std::random(C++11)
#include <numeric>			//std::accumulate

int main(void) {

	//test用
	//std::ifstream in("test.txt");
	//std::cin.rdbuf(in.rdbuf());

	//const unsigned int MODULO = 1000000007;	//MODULO 10^9+7用

	int N;
	std::cin >> N;
	std::vector<int> A(N);
	
	for (int i = 0; i < N; i++) {
		std::cin >> A[i];
	}
	std::sort(A.begin(), A.end());

	int ans = 0;
	if (A[0] != A[1]) {
		ans++;
	}
	for (int i = 1; i < N - 1; i++) {
		if (A[i - 1] != A[i] && A[i] != A[i + 1]) {
			ans++;
		}
	}
	if (A[N - 2] != A[N - 1]) {
		ans++;
	}

	std::cout << ans << std::endl;

}