#define _GLIBCXX_DEBUG 1
#define _GLIBCXX_DEBUG_PEDANTIC 1
#define _FORTIFY_SOURCE 2

#include <bits/stdc++.h>

int main() {
    std::set<int> set{1,2,3,4,5};
    auto it = set.begin();
    set.erase(set.begin());
    std::cout << *it << std::endl;
}