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#include <iostream>
#include <set>
using namespace std;

int main() {
	set<int> set1;
	set1.insert(1);
	set1.insert(2);
	set1.insert(3);
	set1.insert(1);

	cout << set1.count(1) << endl;	// 1
	cout << set1.count(2) << endl;	// 1
	cout << set1.count(3) << endl;	// 1
	cout << set1.count(4) << endl;	// 0
	
	for (auto it : set1) {
		cout << it << " ";
	}
	cout << endl;
	// 1 2 3
	return 0;
}