#include <iostream>
#include <set>

int main() {
    // Create a set object holding integers
    std::set<int> mySet {1, 2, 3, 4, -5};
    
    if (mySet.find(1) != mySet.end()) {
        std::cout << "1 : is a element of mySet" << std::endl;   
    } else {
        std::cout << "1 : is not an element of myset" << std::endl;
    }

    if (mySet.find(12) != mySet.end()) {
        std::cout << "12 : is a element of mySet" << std::endl;   
    } else {
        std::cout << "12 : is not an element of myset" << std::endl;
    }    

    return 0;
}