I installed msys2 and tried running a simple hello world c++ program

#include<iostream>

int main()
{
    int a;
    std::cout<<"Hello World!n";
    std::cin>>a;
    return 0;
}

when running the executable produced by g++.exe, the command prompt freezes for a bit and then the program exits with no output.

some findings:
The C alternative of the hello world works completely fine.
I tried this code:

#include<iostream>
#include<stdio.h>

int main()
{
    int a;
    printf("something somethingn");
    std::cout<<"Hello Worldn";
    printf("Exitn");
    return 0;
}

and the output was:

E:Test>g++ main.cpp

E:Test>a
something something

E:Test>

System info:
Windows 10
Mingw-w64-ucrt toolchain

Solution I tried:
I tried installing some “distro” mentioned in this post
and it worked.
Using the argument “-static-libstdc++” also works.
But I want to know why was it not working before adding the argument. And what file do I need in order to build it “dynamically” or how do I shorten the command to compile statically.(I am satisficed with the solution in the post but wanna know more about the causes and the fix)