#include <windows.h>

LRESULT CALLBACK
WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd, uMsg, wParam, lParam);
    }
    return 0;
}

INT WINAPI
WinMain(HINSTANCE   hInstance,
        HINSTANCE   hPrevInstance,
        LPSTR       lpCmdLine,
        INT         nCmdShow)
{
    WNDCLASS wc = { 0, WindowProc };
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_3DFACE + 1);
    wc.lpszClassName = "AAA";
    RegisterClass(&wc);

    HWND hwnd = CreateWindowEx(WS_EX_TOPMOST,
        "AAA", "AAA", WS_POPUP | WS_SIZEBOX | WS_SYSMENU,
        0, 0, 100, 100,
        NULL, NULL, hInstance, NULL);

    ShowWindow(hwnd, SW_SHOWNORMAL);
    UpdateWindow(hwnd);

    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        DispatchMessage(&msg);
    }
    return 0;
}