#include <memory>
#include <iostream>

class Bin_Tree {
public:
	Bin_Tree(const int &v) :left{ nullptr }, right{ nullptr }, val{ v }, doubled{ false } {};
	void insert(const int &v) {
		if (v == val) doubled = true;
		else if (v < val) {
			if (left) left->insert(v);
			else left = std::unique_ptr<Bin_Tree>(new Bin_Tree(v));
		}
		else {
			if (right) right->insert(v);
			else right = std::unique_ptr<Bin_Tree>(new Bin_Tree(v));
		}
	}
	int count_unique() const {
		int sum = 0;
		if (left) sum += left->count_unique();
		if (right) sum += right->count_unique();
		if (doubled) return sum;
		else return sum + 1;
	}
private:
	std::unique_ptr<Bin_Tree> left, right;
	const int val;
	bool doubled;
};
int main() {
	int n;
	std::cin >> n;
	Bin_Tree root(0);
	for (; n > 0; --n) {
		int a;
		std::cin >> a;
		root.insert(a);
	}
	std::cout << root.count_unique() - 1 << std::endl;
	return 0;
}