insert into a vector more than once c++

#include <iostream>
#include <vector>

int main() {
    std::vector<int> numbers; // Create an empty vector to store integers

    // Insert values into the vector using push_back() method
    numbers.push_back(10); // Insert 10 into the vector
    numbers.push_back(20); // Insert 20 into the vector
    numbers.push_back(30); // Insert 30 into the vector

    // Inserting values at a specific position using insert() method
    auto it = numbers.begin(); // Create an iterator pointing to the beginning of the vector
    it = numbers.insert(it + 1, 15); // Insert 15 at the second position in the vector

    // Inserting multiple values at a specific position using insert() method
    std::vector<int> moreNumbers = {25, 35, 45}; // Create a vector with values to insert
    numbers.insert(it + 2, moreNumbers.begin(), moreNumbers.end()); // Insert values from moreNumbers starting at the third position

    // Display the elements in the vector
    std::cout << "Vector elements after insertion:" << std::endl;
    for (const auto &num : numbers) {
        std::cout << num << " ";
    }
    std::cout << std::endl;

    return 0;
}