#include <vector>
#include <iostream>

class MyClass{
    public:
    int val=0;
    MyClass(int val)
    :val(val){};
};

int main() {
    std::vector<MyClass> myitems;
    for (int i=0;i<20;i++) {
        myitems.push_back({i});
    }
    for (int i=0;i<myitems.size();i++) {
        (&myitems[i])->val++;
        std::cout<<myitems[i].val<<"\n";
    }
}