#include <iostream>
#include <vector>

// Begin with numbers 1, 2, 3 in the list already
int main()
{
    // In C++17 we can omit the int if the compiler can determine the type.
    std::vector<int> numbers { 1, 2, 3 };
    int input;
    while (std::cin >> input) {
        numbers.push_back(input);
    }
    std::cout << "1st element: " << numbers.at(0) << "\n"; // slower, safer
    std::cout << "2nd element: " << numbers[1] << "\n"; // faster, less safe
    std::cout << "Max size before realloc: " << numbers.capacity() << "\n";
    for (int n : numbers) {
        std::cout << n << "\n";
    }
}