4- Fire the Bug - C++

The code with the bug:

#include <iostream>
#include <string>

int main()
{
  std::string user_input;

  std::cout << "Enter your name: ";
  std::cin >> user_input;

  std::cout << "Hello, " << user_input << "!" << std::endl;
  
  return 0;
}
  

What could fix the bug in the code above?